Health Library

Our Health Library information does not replace the advice of a doctor. Please be advised that this information is made available to assist our patients to learn more about their health. Our providers may not see and/or treat all topics found herein.

Category: Hormones

Abnormal Uterine Bleeding
This topic is for women who want to learn about or have been diagnosed with abnormal uterine bleeding (AUB). Abnormal uterine bleeding has several causes. If you don't know what kind of bleeding you have, see the topic Abnormal...

Abnormal Uterine Bleeding: Should I Have a Hysterectomy?
Guides through decision to treat abnormal uterine bleeding. Explains symptoms that doctor would look for before recommending treatment. Covers benefits and risks. Includes an interactive tool to help you make your decision.

Addison's Disease
Addison's disease develops when the adrenal glands, which are above the kidneys, are not able to make enough of the hormones cortisol and, sometimes, aldosterone. Your body needs both of these hormones to work as it should. Cortisol...

Adrenocortical Carcinoma Treatment (PDQ®): Treatment - Patient Information [NCI]
Adrenocortical carcinoma is a rare disease in which malignant (cancer) cells form in the outer layer of the adrenal gland. There are two adrenal glands. The adrenal glands are small and shaped like a triangle. One adrenal gland sits on top of each kidney. Each adrenal gland has two parts. The outer layer of the adrenal...

Adrenocorticotropic Hormone
An adrenocorticotropic hormone test measures the level of adrenocorticotropic hormone (ACTH) in the blood to check for problems with the pituitary gland and adrenal glands. ACTH is made in the pituitary gland in response to ...

Aldosterone in Blood
An aldosterone test measures the level of aldosterone (a hormone made by the adrenal glands), in the blood. Aldosterone helps regulate sodium and potassium levels in the body. This helps control blood pressure and the...

Aldosterone in Urine
An aldosterone test measures the level of aldosterone (a hormone made by the adrenal glands) in the urine. Aldosterone helps regulate sodium and potassium levels in the body. This helps control blood pressure and the...

Amylase
An amylase test measures the amount of this enzyme in a sample of blood taken from a vein or in a sample of urine. Normally, only low levels of amylase are found in the blood or urine. But if the pancreas or salivary glands...

Anabolic Steroids
Anabolic steroids are synthetic substances similar to the male hormone testosterone. Doctors prescribe them to treat problems such as delayed puberty and other medical problems that cause the body to make very low amounts of...

Antithyroid Antibodies Test
The immune system may produce antithyroid antibodies. These antibodies destroy thyroid tissue. This test can find out if you have these antibodies. High levels of antithyroid antibodies may mean that you have autoimmune hypothyroidism...

Antithyroid Antibody Tests
Thyroid antibody tests measure the levels of antibodies that can destroy thyroid tissue or make the cells produce thyroid hormones. They are blood tests. Antibodies that destroy thyroid tissue can lead to hypothyroidism (underactive thyroid). ...

Basic Metabolic Panel
Briefly discusses basic metabolic panel, a blood test that measures your sugar (glucose) level, electrolyte and fluid balance, and kidney function. Provides links to more info on specific tests such as blood urea nitrogen, creatinine, and potassium tests.

Birth Control Hormones: The Implant
The implant is used to prevent pregnancy. It's a thin rod about the size of a matchstick that is inserted under the skin (subdermal) on the inside of your arm. The implant releases the hormone progestin to prevent pregnancy. Progestin prevents...

Birth Control Hormones: The Mini-Pill
Mini-pills are used to prevent pregnancy. They release a regular dose of a hormone called progestin. They are different from regular combination birth control pills. Those contain progestin and another hormone called estrogen. Progestin prevents...

Birth Control Hormones: The Patch
The patch is used to prevent pregnancy. It looks like a bandage and is put on the skin of your belly, rear end (buttocks), upper arm, or upper body (but not on a breast). The patch releases a regular dose of the hormones estrogen and progestin....

Birth Control Hormones: The Pill
Combination pills are used to prevent pregnancy. Most people call them "the pill." Combination pills release a regular dose of two hormones, estrogen and progestin. They prevent pregnancy in a few ways. They thicken the mucus in the cervix. This...

Birth Control Hormones: The Ring
The ring is used to prevent pregnancy. It's a soft plastic ring that you put into your vagina. It's also called the vaginal ring. The ring releases a regular dose of the hormones estrogen and progestin. These hormones prevent pregnancy in three...

Birth Control Hormones: The Shot
The shot is used to prevent pregnancy. You get the shot in your upper arm or rear end (buttocks). The shot gives you a dose of the hormone progestin. The shot is often called by its brand name, Depo-Provera. Progestin prevents pregnancy in these...

Black Cohosh for Menopause Symptoms
Black cohosh, also known as black snakeroot or bugbane, is a medicinal root. It is used to treat women's hormone-related symptoms, including premenstrual syndrome (PMS), menstrual cramps, and menopausal symptoms. Black cohosh contains...

Blood Glucose
Discusses blood glucose tests used to diagnose diabetes and prediabetes. Covers types of tests, including fasting blood sugar, 2-hour postprandial blood sugar, random blood sugar, and oral glucose tolerance. Discusses how to prepare and what results mean.

Brain Natriuretic Peptide (BNP) Test
Gives info on test for BNP hormone to tell how well the heart works. Tells how BNP checks for heart failure. Tells how to get ready for test. Includes what results mean. Also discusses things that affect test results, such as some health problems and medicines.

C-Peptide
Discusses C-peptide test, used to tell the difference between type 1 or type 2 diabetes, find the cause of hypoglycemia, or check whether a pancreas tumor (insulinoma) was completely removed. Discusses how the test is done and how to prepare for it.

Calcium (Ca) in Blood
Covers calcium (Ca) test to examine calcium level in blood, not stored in bones. Explains why test is done and how to prepare. Includes possible results and what they may mean. Looks at what may affect test results.

Calcium (Ca) in Urine
A test for calcium in urine is a 24-hour test that checks the amount of calcium that is passed from the body in the urine. Calcium is the most common mineral in the body and one of the most important. The body needs it to build and...

Catecholamines in Blood
A test for catecholamines measures the amount of the hormones epinephrine, norepinephrine, and dopamine in the blood. These catecholamines are made by nerve tissue, the brain, and the adrenal glands. Catecholamines help the body...

Catecholamines in Urine
Catecholamines (say "kat-uh-KOH-luh-meens") are hormones made mostly by your adrenal glands as a reaction to stress. When you feel stressed, these hormones increase heart rate, blood pressure, breathing rate, muscle strength, and mental...

Chloride (Cl)
Covers chloride test to measure the level of chloride in blood or urine. Explains why test is done and how to prepare. Includes possible results and what they may mean. Looks at what may affect test results.

Chronic Fatigue: Antidepressants
Antidepressants do not cure myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). They may relieve symptoms such as fatigue, sleep problems, difficulty concentrating, and pain. But they will not affect the course of the illness or the...

Chronic Fatigue: Changing Your Schedule
You may find it helpful to change your schedule to take advantage of times when you have more energy and feel less tired. Keep a diary for a week or so, and record the times of day when you have energy and when you are tired. If there is a...

Chronic Fatigue: Getting Support
People who have chronic health problems, such as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), often benefit from support groups. These groups can be a good source of information and tips for managing your illness and a chance...

Complications From Klinefelter Syndrome
Males who have Klinefelter syndrome may have an increased risk of: Learning disabilities. Skin conditions (eczema and ulcers of the leg). Diseases of blood vessels in the brain (cerebrovascular disease), such as stroke. Autoimmune...

Comprehensive Metabolic Panel
A comprehensive metabolic panel is a blood test that measures your sugar (glucose) level, electrolyte and fluid balance, kidney function, and liver function. Glucose is a type of sugar your body uses for energy. Electrolytes keep ...

Cortisol in Blood
A cortisol test is done to measure the level of the hormone cortisol in the blood. The cortisol level may show problems with the adrenal glands or pituitary gland. Cortisol is made by the adrenal glands. Cortisol levels go up...

Cortisol in Urine
A cortisol test measures the level of the hormone cortisol in a 24-hour sample of urine. The cortisol level may show problems with the adrenal glands or the pituitary gland. Cortisol is made by the adrenal glands. Cortisol...

Cushing's Syndrome
Cushing's syndrome is a rare problem that happens when you have too much of the hormone cortisol in your body. Cortisol is especially important in controlling blood pressure and metabolism. But it affects almost every area of...

Cushing's Syndrome: Corticotropin-Releasing Hormone
The corticotropin-releasing hormone (CRH) stimulation test helps find out if a pituitary tumor may be causing Cushing's syndrome. It is sometimes done with an inferior petrosal sinus sampling (IPSS) test. In these tests, a small tube called...

DHEA-S Test
DHEA-S (dehydroepiandrosterone sulfate) is a male hormone (androgen) that is made in the adrenal glands. The body turns it into testosterone. A test for DHEA-S checks the level of this hormone in the blood. Testosterone affects sexual features and...

Dawn Phenomenon and the Somogyi Effect
The dawn phenomenon and the Somogyi effect cause high blood sugar levels, especially in the morning before breakfast, in people who have diabetes. The dawn phenomenon is a normal rise in blood sugar as a person's body prepares to wake...

Diabetes in Children: Checking Blood Sugar in a Child
Describes monitoring blood sugar levels in children with diabetes. Covers list of supplies needed, including blood sugar meter, testing strips, and lancet. Gives step-by-step instructions. Links to info on type 1 and type 2 diabetes.

Diabetes in Children: Counting Carbs
Teaches counting carbs to help you and your child plan meals to manage diabetes and control blood sugar. Explains why carb counting is important. Includes links to more info on counting carbs if you use insulin and on type 1 and type 2 diabetes.

Diabetes in Children: Giving Insulin Shots to a Child
If your child doesn't want to feel the insulin needle, your child's doctor can prescribe an indwelling subcutaneous cannula. A small needle is used to insert a soft tube into a place where you give your child an insulin shot, such as the belly. The...

Diabetes in Children: Preparing a Care Plan for School
A diabetes care plan will help your child's teachers and other school staff know when and how to manage your child's diabetes. For example, if your child needs to eat shortly after taking insulin or to have a snack in class, then a...

Diabetes in Children: Preventing High Blood Sugar
Discusses high blood sugar (also called hyperglycemia) in children with diabetes. Covers symptoms. Offers tips on preventing high blood sugar emergencies. Covers when to seek emergency care.

Diabetes in Children: Treating Low Blood Sugar
Low blood sugar, also called hypoglycemia, occurs when the sugar (glucose) level in the blood of a person with diabetes drops below what the body needs to function normally. Taking too much insulin, not eating enough food or skipping...

Diabetes-Related High and Low Blood Sugar Levels
Discusses high and low blood sugar levels caused by diabetes. Suggests when to check blood sugar levels. Covers symptoms. Offers home treatment and prevention tips. Includes info on diabetes emergencies.

Diabetes: Should I Get an Insulin Pump?
Guides you through decision to get an insulin pump to manage type 1 or type 2 diabetes. Discusses who makes a good candidate for an insulin pump. Covers benefits and risks. Includes an interactive tool to help you make your decision.

Diabetic Ketoacidosis (DKA)
Diabetic ketoacidosis (DKA) is a life-threatening condition that develops when cells in the body are unable to get the sugar (glucose) they need for energy because there is not enough insulin. When the sugar cannot get into the cells, it...

Emotions and Menopause
The transition to postmenopause is a normal part of the aging process. It is also a time of physical changes. You can expect some emotional responses to these changes, both positive and negative. Menopause does not create serious emotional...

Endometriosis: Should I Have a Hysterectomy and Oophorectomy?
Guides you through decision to have hysterectomy and oophorectomy to treat endometriosis. Covers risks of treating and not treating. Covers how well hysterectomy and removal of ovaries works. Includes interactive tool to help you make your decision.

Estrogens
An estrogen test measures the level of the most important estrogen hormones in a blood or urine sample. It measures estradiol, estriol, and estrone. Estradiol is the most common type of estrogen measured for nonpregnant women. The...

Gestational Diabetes
Discusses gestational diabetes (diabetes that develops during pregnancy). Discusses symptoms and how it's diagnosed. Covers treatment with healthy food choices, exercise, medicine and insulin to control blood sugar levels.

Glycohemoglobin (HbA1c, A1c)
Covers blood test that checks the amount of sugar (glucose) bound to hemoglobin. Explains that test is done to check how well you are managing your diabetes. Covers how it is done and discusses results.

Growth Hormone
A growth hormone (GH) test measures the amount of human growth hormone (GH) in the blood. GH is made by the pituitary gland and is needed for growth. It plays an important role in how the body uses food for energy (metabolism). ...

Gynecomastia
Gynecomastia is overdevelopment of the male breast. In response to too much estrogen (a female hormone) or too little testosterone (a male hormone), the glandular tissue of the breast swells and forms a breast bud (enlarged breast)....

Home Blood Glucose Test
Discusses test to measure blood sugar (glucose) levels in those who have diabetes. Covers why and how it is done. Looks at what might affect the test. Covers risks.

Hormonal Factors in Erection Problems
Hormonal factors may play a role in erection problems (erectile dysfunction). Men who produce low levels of the hormone testosterone (a condition known as hypogonadism) may have decreased sexual desire. A blood test is usually done if your...

Hormone Inhibin A
The inhibin A test is done to measure the amount of this hormone in a pregnant woman's blood to see if the baby may have Down syndrome. Inhibin A is made by the placenta during pregnancy. The level of inhibin A in the blood is...

Hormones
Has info on hypothyroidism, hyperthyroidism, and thyroid tests. Also has links to info on PMS and polycystic ovary syndrome.

Hot Flashes and Menopause
A hot flash is a sudden sensation of intense body heat, often with profuse sweating and reddening of the head, neck, and chest. These symptoms can occur with mild to severe heart palpitations, anxiety, irritability and, rarely, panic. Hot...

How the Body Controls Blood Sugar
The bloodstream carries glucose-a type of sugar produced from the digestion of carbohydrates and other foods-to provide energy to cells throughout the body. Unused glucose is stored mainly in the liver as glycogen. Insulin, glucagon, and...

Human Chorionic Gonadotropin (HCG)
The human chorionic gonadotropin (hCG) test is done to check for the hormone hCG in blood or urine. Some hCG tests measure the exact amount. Some just check to see if the hormone is present. HCG is made by the placenta during...

Hyperparathyroidism
Hyperparathyroidism means that one or more of your four parathyroid glands may be too active. These are tiny glands in the neck, behind the thyroid gland. When they're too active, they make too much parathyroid hormone (PTH). This hormone helps...

Hyperthyroidism
Discusses hyperthyroidism and what happens to the body's metabolism if the thyroid gland is overactive. Explains how Graves' disease usually causes an overactive thyroid. Describes symptoms. Covers exams and tests to diagnose it. Provides info on treatment.

Hyperthyroidism: Age-Related Symptoms
Symptoms of hyperthyroidism may be different depending on your age. Young adults are likely to: Have an irregular heartbeat. Feel nervous. Have problems sleeping. Have soft stools and more stools than usual. Feel uncomfortable in warm...

Hyperthyroidism: Graves' Ophthalmopathy
In Graves' ophthalmopathy the tissues and muscles behind the eyes become swollen. The eyeballs may stick out farther than normal. This can occur before, after, or at the same time as other signs of hyperthyroidism. Most people who develop...

Hyperthyroidism: Medicines for Symptoms
Other medicines that doctors may use to treat the symptoms of hyperthyroidism include: Beta-blocker medicines. Examples are propranolol (such as Inderal), atenolol (Tenormin), and metoprolol (Lopressor). These drugs control a fast...

Hyperthyroidism: Should I Use Antithyroid Medicine or Radioactive Iodine?
Guides you through decision to use antithyroid medicine or radioactive iodine to treat hyperthyroidism. List benefits for and against each of the treatments. Includes an interactive tool to help you make your decision.

Hypoglycemia (Low Blood Sugar) in People Without Diabetes
Discusses hypoglycemia (low blood sugar) in people who don't have diabetes. Explains blood sugar (glucose) in the body. Describes symptoms of mild, moderate, and severe hypoglycemia. Covers treatment for sudden episodes and emergency situations.

Hypothyroidism
Covers hypothyroidism, which happens when the thyroid doesn't make enough thyroxine (T4) and triiodothyronine (T3) hormones. Includes causes like thyroiditis. Covers tests for TSH, T4, and T3. Also includes info on treatment with medicine such as levothyroxine.

Hypothyroidism in Infants, Children, and Teens
Severe hypothyroidism in infancy results in slow growth, significant intellectual disability, and developmental delays. Symptoms are seldom apparent at birth. The age at which they appear and their severity depends on how well the infant's...

Hysterectomy and Oophorectomy: Should I Use Estrogen Therapy (ET)?
Guides you through the decision to use estrogen therapy (ET) after hysterectomy and oophorectomy. Lists the benefits and risks of ET. Suggests other treatments you can try. Includes interactive tool to help you make your decision.

Infertility: Questions to Ask About Medicine or Hormone Treatment
When considering whether to try medicine or hormone treatment for infertility, ask: Whether there are any possible long-term risks related to the proposed treatment. Whether you need to change your sexual activities during treatment. Your...

Ketones
A ketone test checks for ketones in your blood or urine. Ketones are substances that are made when the body breaks down fat for energy. Normally, your body gets the energy it needs from carbohydrate in your diet. But stored fat...

Klinefelter Syndrome
Klinefelter syndrome is a genetic disorder that affects males. Klinefelter syndrome occurs when a boy is born with one or more extra X chromosomes. Most males have one Y and one X chromosome. Having extra X chromosomes can cause...

Laparoscopic Ovarian Drilling (Ovarian Diathermy) for PCOS
Laparoscopic ovarian drilling is a surgical treatment that can trigger ovulation in women who have polycystic ovary syndrome (PCOS). Electrocautery or a laser is used to destroy parts of the ovaries. This surgery is not commonly...

Levothyroxine
Make sure you know about each of the medicines you take. This includes why you take it, how to take it, what you can expect while you're taking it, and any warnings about the medicine. The information provided here is general. So be sure to read the...

Living With More Than One Health Problem
Many people have more than one long-term (chronic) health problem. You may be one of them. For example, you may have high blood pressure and diabetes, or you may have high blood pressure, diabetes, and heart failure. When you...

Low Testosterone
Men who have low testosterone do not make enough of the male hormone called testosterone. This hormone allows men to produce sperm and to develop and keep normal physical male traits. Low testosterone is also called testosterone deficiency or...

Luteinizing Hormone
A luteinizing hormone test measures the amount of luteinizing hormone (LH) in a sample of blood or urine. LH is produced by the pituitary gland. In women, LH helps regulate the menstrual cycle and egg production (ovulation). How...

Medical History for PMS
Your medical history is an important tool for your doctor in determining whether you have premenstrual syndrome (PMS). Your medical history includes your: Record of your PMS symptoms, menstrual dates, and ovulation dates, if...

Melatonin
Melatonin is a hormone made by the pineal gland, a small gland in the brain. Melatonin helps control your sleep and wake cycles. Very small amounts of it are found in foods such as meats, grains, fruits, and vegetables. You can also...

Menopause and Perimenopause
Discusses what happens in the body during menopause or perimenopause. Describes physical and emotional symptoms like hot flashes and mood swings. Discusses treatment with lifestyle changes like diet and exercise. Also covers hormone therapy.

Menopause: Managing Hot Flashes
Discusses options for managing perimenopause- and menopause-related hot flashes. Explains what hot flashes are. Discusses lifestyle changes that may help hot flashes. Looks at hormone therapy (HT) and treatment with medicines and herbs.

Menopause: Should I Use Hormone Therapy (HT)?
Guides you through the decision to use hormone therapy (HT) for menopause symptoms. Explains what menopause is and what to expect. Lists risks and benefits of HT and other treatments to try. Includes interactive tool to help you decide.

Menopause: Wild Yam and Progesterone Creams
Wild yam and progesterone creams are available without a prescription and are marketed for relieving perimenopausal symptoms. Wild yam. Although wild yam cream is marketed as a source of natural progesterone, it does not contain progesterone,...

Menstruation: Not Having a Period by Age 15
The menstrual cycle is the series of changes a woman's body goes through to prepare for a possible pregnancy. Most girls start having periods between the ages of 11 and 15. A girl who has not had her first period by age 15 has what is called...

Metabolic Syndrome
Discusses metabolic syndrome, a group of health problems that increase risk for diabetes and heart disease (coronary artery disease). Covers risk factors like obesity, high blood pressure, and high cholesterol. Covers diet and exercise to improve health.

Missed Periods and Endurance Training
If you participate in endurance sports, you may miss periods or stop menstruating. This is called secondary amenorrhea, and it occurs because your ovaries are not producing enough estrogen. It is believed that stress and low body...

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) (say "my-AL-jik en-seh-fuh-loh-my-uh-LY-tus") is a condition that makes you feel so tired that you can't do all of your normal, daily activities. There are other symptoms too,...

Night Sweats
Night sweats are heavy sweating during sleep. This kind of sweating is different than the occasional sweating people have from sleeping deeply, being in a warm room, or having too many blankets. Night sweats are often so heavy that your clothing and...

Oral Glucose Tolerance Test
Discusses oral glucose tolerance test that measures glucose (blood sugar) levels. Explains that test checks for gestational diabetes, prediabetes, and diabetes. Covers the types of tests done and how to prepare for them.

Orchiectomy for Prostate Cancer
Orchiectomy is the removal of the testicles. The penis and the scrotum, the pouch of skin that holds the testicles, are left intact. An orchiectomy is done to stop most of the body's production of testosterone, which prostate cancer...

Overnight Dexamethasone Suppression Test
The overnight dexamethasone suppression test checks to see how taking a steroid medicine called dexamethasone changes the levels of the hormone cortisol in the blood. This test checks for a condition in which large amounts of...

Oxytocin
Oxytocin is a hormone released from the pituitary gland in the brain. During pregnancy, oxytocin causes labor contractions to begin. Oxytocin also is released when a woman's breasts are stimulated by suckling or pumping, causing milk to move...

PMS: Ways to Record Your Symptoms
There are several ways to keep a menstrual diary of your PMS symptoms. Diaries that require daily recording are more reliable in tracking your symptoms. Calendars without marks for a day may mean you forgot to record for that day rather...

Pancreatic Cancer
Describes pancreatic cancer. Talks about symptoms and what tests are used to diagnose it. Provides treatment details. Lists factors that raise your risk.

Pancreatic Cancer Treatment (PDQ®): Treatment - Patient Information [NCI]
Pancreatic cancer is a disease in which malignant (cancer) cells form in the tissues of the pancreas. The pancreas is a gland about 6 inches long that is shaped like a thin pear lying on its side. The wider end of the pancreas is called the head, the middle section is called the body, and the narrow end is called the...

Pancreatic Neuroendocrine Tumors (Islet Cell Tumors) Treatment (PDQ®): Treatment - Patient Information [NCI]
Pancreatic neuroendocrine tumors form in hormone-making cells (islet cells) of the pancreas. The pancreas is a gland about 6 inches long that is shaped like a thin pear lying on its side. The wider end of the pancreas is called the head, the middle section is called the body, and the narrow end is called the tail. The...

Parathyroid Cancer Treatment (PDQ®): Treatment - Patient Information [NCI]
Parathyroid cancer is a rare disease in which malignant (cancer) cells form in the tissues of a parathyroid gland. The parathyroid glands are four pea-sized organs found in the neck near the thyroid gland. The parathyroid glands make parathyroid hormone (PTH or parathormone). PTH helps the body use and store calcium to...

Parathyroid Gland and Kidney Stones
The parathyroid glands are four tiny glands located within the thyroid gland in the neck. They produce parathyroid hormone, which helps control the amount of calcium in the blood. If your parathyroid gland is too big (enlarged), it can...

Parathyroid Hormone
Covers why and how parathyroid hormone tests are done. Covers what possible results might mean. Includes info on what might affect the test.

Pheochromocytoma and Paraganglioma Treatment (PDQ®): Treatment - Patient Information [NCI]
Pheochromocytoma and paraganglioma are rare tumors that come from the same type of tissue. Paragangliomas form in nerve tissue in the adrenal glands and near certain blood vessels and nerves. Paragangliomas that form in the adrenal glands are called pheochromocytomas. Paragangliomas that form outside the adrenal glands...

Pituitary Tumors Treatment (PDQ®): Treatment - Patient Information [NCI]
A pituitary tumor is a growth of abnormal cells in the tissues of the pituitary gland. Pituitary tumors form in the pituitary gland, a pea-sized organ in the center of the brain, just above the back of the nose. The pituitary gland is sometimes called the "master endocrine gland" because it makes hormones that affect...

Polycystic Ovary Syndrome (PCOS)
Discusses polycystic ovary syndrome, a problem in which a woman's hormones are out of balance. Discusses PCOS early symptoms like heavy bleeding or facial hair. Also covers more serious symptoms like miscarriages or infertility. Includes info on treatment.

Potassium (K) in Blood
Discusses blood test to check level of potassium (K) in blood. Includes info on what affects potassium levels in the body such as kidney function, blood pH, and hormones. Explains how and why test is done. Covers what results mean.

Prediabetes
Covers warning signs that you may be at risk for type 2 diabetes. Includes causes and symptoms. Looks at lifestyle changes to get your blood sugar levels back to a normal range. Includes tips on diet, weight loss, and exercise.

Premenstrual Syndrome (PMS)
Covers symptoms of PMS such as bloating, muscle aches, and mood swings. Discusses possible causes and what increases your risk. Covers treatment with lifestyle changes, antidepressants, or birth control pills. Covers surgery for severe form (PMDD).

Progesterone
A progesterone test measures the amount of the hormone progesterone in a blood sample. Progesterone is a female hormone produced by the ovaries during release of a mature egg from an ovary (ovulation). Progesterone helps prepare the...

Prolactin
A prolactin test measures the level of the hormone prolactin, which is made by the pituitary gland, in your blood. Pregnant women have high levels of prolactin, which helps make breast milk. During pregnancy, prolactin levels increase by...

Radioactive Iodine
Radioactive iodine, given in a capsule or liquid form, is absorbed and concentrated by the thyroid gland. The treatment destroys thyroid tissue but does not harm other tissue in the body. See a picture of the thyroid gland. While...

Radioactive Iodine Uptake Test
A radioactive iodine uptake (RAIU) test uses a radioactive tracer and a special probe to measure how much tracer the thyroid gland absorbs from the blood. The test can show how much tracer is absorbed by the thyroid gland. The...

Radioactive Iodine for Hyperthyroidism
Radioactive iodine is a medicine that you take one time. After you swallow it, it is taken up by your thyroid gland. Depending on the dosage used, the radioactivity in the iodine destroys most or all of the tissue in your thyroid gland,...

Relieving Menstrual Pain
Discusses ways to relieve pain from menstrual cramps that usually start before or at the beginning of your period. Includes steps you can take such as applying heat on your belly or getting regular exercise. Covers over-the-counter medicines that can help.

Renin Assay
A renin assay blood test is done to find the cause of high blood pressure (hypertension). Renin is an enzyme made by special cells in the kidneys. Renin works with aldosterone (a hormone made by the adrenal glands) and...

Secondary Adrenocortical Insufficiency
Secondary adrenocortical insufficiency is a condition in which a lack of adrenocorticotropic hormone (ACTH) prevents the body from producing enough cortisol. Production of cortisol is controlled by the action of ACTH. ACTH is produced by...

Sick-Day Guidelines for People With Diabetes
When you are sick, your body reacts by releasing hormones to fight infection. But these hormones raise blood sugar levels and at the same time make it more difficult for insulin to lower blood sugar. When you have diabetes, even a...

Soy for Menopause Symptoms
Soy is high in isoflavones. Isoflavones are a type of phytoestrogen. Phytoestrogens are chemicals found in plants that work like estrogens. In some ways, the human body can use them like estrogens. Menopause symptoms. Soy...

Storing Insulin and Prefilling Syringes
Insulin can become damaged and ineffective if it is not stored properly. Unopened insulin that is packaged in small glass bottles (vials) should be stored in the refrigerator. Liquid insulin that is packaged in small cartridges (containing...

Subclinical Hyperthyroidism
You may have a very mild form of hyperthyroidism called subclinical hyperthyroidism if your thyroid tests show that: Your thyroid-stimulating hormone (TSH) levels are low. Your thyroid hormones thyroxine (T4) and triiodothyronine ...

Subclinical Hypothyroidism
A doctor diagnoses mild, or subclinical, hypothyroidism through a medical history and physical exam. If your doctor suspects that you have subclinical hypothyroidism, you will have lab tests to confirm the diagnosis. Subclinical hypothyroidism...

Symptoms of High Blood Sugar
High blood sugar (hyperglycemia) is most often seen in people who have diabetes that isn't well controlled. The symptoms of high blood sugar can be mild, moderate, or severe. If your blood sugar levels are consistently higher than your target...

Taking Birth Control Pills With Other Medicines
Some medicines can interfere with how birth control pills work. For example, you may not be protected from pregnancy while you are taking other medicines that affect liver metabolism. The vaginal ring and skin patch contain combination...

Testosterone
A testosterone test checks the level of this male hormone (androgen) in the blood. Testosterone affects sexual features and development. In men, it is made in large amounts by the testicles. In both men and women, testosterone is...

Testosterone
Make sure you know about each of the medicines you take. This includes why you take it, how to take it, what you can expect while you're taking it, and any warnings about the medicine. The information provided here is general. So be sure to read the...

Testosterone and Osteoporosis
Testosterone is one of the hormones needed for sexual development. Although testosterone is present in both men and women, it is considered a male sex hormone (androgen) and is produced in much higher amounts in men than in women. Testosterone...

Thyroid Biopsy
A thyroid biopsy is a procedure in which a small sample of tissue is removed from the thyroid gland and looked at under a microscope for cancer, infection, or other thyroid problems. The thyroid gland is found in front of the...

Thyroid Cancer
Discusses causes and symptoms of thyroid cancer. Covers factors that increase risk, including exposure to radiation. Discusses diagnosis and treatment with surgery, radioactive iodine, and thyroid hormone therapy.

Thyroid Cancer Treatment (PDQ®): Treatment - Patient Information [NCI]
Thyroid cancer is a disease in which malignant (cancer) cells form in the tissues of the thyroid gland. The thyroid is a gland at the base of the throat near the trachea (windpipe). It is shaped like a butterfly, with a right lobe and a left lobe. The isthmus, a thin piece of tissue, connects the two lobes. A healthy...

Thyroid Hormone Production and Function
The thyroid gland uses iodine from food to make two thyroid hormones: triiodothyronine (T3) and thyroxine (T4). It also stores these thyroid hormones and releases them as they are needed. The hypothalamus and the pituitary gland, which are...

Thyroid Hormone Replacement for Hypothyroidism
Thyroid hormones help regulate the way the body uses energy. You need thyroid hormone replacement when you do not have enough thyroid hormones in your blood (hypothyroidism). Depending on the cause of your hypothyroidism, you may need to take...

Thyroid Hormone Tests
Looks at various tests used to check how well the thyroid gland is working. Covers what results might mean. Also looks at what might affect a test. Offers links to info on other tests that might be useful, including thyroid-stimulating hormone (TSH) test.

Thyroid Hormones
Thyroid hormones are made by the thyroid gland. The thyroid gland makes and releases two thyroid hormones: thyroxine (T4) and triiodothyronine (T3). Thyroid hormones affect every cell and all the organs of the body. Too much thyroid hormone...

Thyroid Nodules
Thyroid nodules are growths or lumps in the thyroid gland in the front of your neck. This gland controls how your body uses energy. Most thyroid nodules are not cancer and do not cause problems. Many don't even need...

Thyroid Scan
A thyroid scan uses a radioactive tracer and a special camera to measure how much tracer the thyroid gland absorbs from the blood. The tracer can be swallowed or can be injected into a vein. It travels through your body, giving off radiation...

Thyroid Storm
Thyroid storm (thyroid crisis) is a potentially life-threatening condition for people who have hyperthyroidism. Thyroid storm happens when your thyroid gland suddenly releases large amounts of thyroid hormone in a short period of time. If you...

Thyroid Surgery
Thyroid surgery is used to treat thyroid nodules, thyroid cancer, and hyperthyroidism. During this procedure, part or all of the thyroid gland is removed. During surgery, an incision is made in the skin. The muscle and other...

Thyroid Testing
Experts do not agree on whether adults who don't have symptoms should have a thyroid test. The American Thyroid Association and the American Association of Clinical Endocrinologists recommend that testing be considered for those older than age...

Thyroid and Parathyroid Ultrasound
Covers imaging test to check the thyroid gland and parathyroid glands. Includes info on problems test checks for, such as lumps in the thyroid gland or enlarged thyroid and parathyroid glands. Covers how it is done. Discusses possible results.

Thyroid-Stimulating Hormone (TSH)
Discusses blood test used to check for thyroid gland problems. Explains how TSH causes thyroid gland to make hormones that help control metabolism. Covers how it is done and test results.

Treating Diabetic Foot Problems
Foot problems in people with diabetes are usually treated by keeping blood sugar levels in a target blood sugar range and by using medicine, surgery, and other types of treatment. When foot problems develop, those problems need prompt treatment...

Type 1 Diabetes
Covers type 1 diabetes, also called juvenile diabetes or insulin-dependent diabetes. Describes how pancreas regulates blood sugar (glucose) levels. Includes info on hypoglycemia and hyperglycemia. Discusses treatments, including insulin.

Type 1 Diabetes: Children Living With the Disease
Covers type 1 diabetes in children. Includes info on managing diabetes. Discusses using glucose monitors for blood glucose testing. Includes links to info on dealing with diabetes in school. Includes info on hypoglycemia and hyperglycemia.

Type 1 Diabetes: Medical History and Physical Exam
Symptoms of type 1 diabetes usually happen quickly. If ignored, the diagnosis of type 1 diabetes may happen in an emergency room or hospital. If your doctor thinks that you might have type 1 diabetes, he or she may ask questions about your...

Type 2 Diabetes
Information on type 2 diabetes. Describes how insulin is made and used by the body. Describes symptoms and how type 2 is treated. Provides info on blood sugar (glucose) levels. Discusses obesity's role in type 2 diabetes. Discusses exercise and diet.

Type 2 Diabetes: Screening for Adults
Talk with your doctor about what is putting you at risk for type 2 diabetes and how often you need to be tested. The United States Preventive Services Task Force (USPSTF) recommends testing for prediabetes and type 2 diabetes in people who are...

Types of Insulin
Insulin is used to treat people who have diabetes. Each type of insulin acts over a specific amount of time. The amount of time can be affected by exercise, diet, illness, some medicines, stress, the dose, how you take it, or where you inject...

Types of Thyroid Cancer
There are different types of thyroid cancer. They are based on what the cells look like under a microscope. Your treatment will depend on which type of thyroid cancer you have. Papillary thyroid cancer (PTC). This is the most common type of...

Uncommon Causes of Hyperthyroidism
Uncommon causes of hyperthyroidism or too much thyroid hormone in the body include: Taking too much thyroid hormone medicine. This can happen if you are taking thyroid hormone to treat thyroid cancer. It can also happen if you take too...

Unwanted Hair in Women
Hirsutism (say "HER-suh-tiz-um") is extra hair on a woman's face or body. This hair is dark and coarse. It grows in a male pattern: on the face, like a man's facial hair, or on the body, especially the chest and back. Usually extra hair growth is...

Whipple Surgery for Pancreatic Cancer
Looks at a type of surgery that removes cancer from the pancreas. Covers why surgery is done and how well it works. Also covers risks.