Hyperthyroidism

What is hyperthyroidism?

Hyperthyroidism, or overactive thyroid, happens when your thyroid gland makes more thyroid hormones than your body needs.

Your thyroid is a small, butterfly-shaped gland in the front of your neck. It makes hormones that control the way the body uses energy. These hormones affect nearly every organ in your body and control many of your body's most important functions. For example, they affect your breathing, heart rate, weight, digestion, and moods. If not treated, hyperthyroidism can cause serious problems with your heart, bones, muscles, menstrual cycle, and fertility. But there are treatments that can help.

What causes hyperthyroidism?

Hyperthyroidism has several causes. They include:

• Graves' disease, an autoimmune disorder in which your immune system attacks your thyroid and causes it to make too much hormone. This is the most common cause.
• Thyroid nodules, which are growths on your thyroid. They are usually benign (not cancer). But they may become overactive and make too much thyroid hormone. Thyroid nodules are more common in older adults.
• Thyroiditis, inflammation of the thyroid. It causes stored thyroid hormone to leak out of your thyroid gland.
• Too much iodine. Iodine is found in some medicines, cough syrups, seaweed and seaweed-based supplements. Taking too much of them can cause your thyroid to make too much thyroid hormone.
• Too much thyroid medicine. This can happen if people who take thyroid hormone medicine for hypothyroidism (underactive thyroid) take too much of it.

Who is at risk for hyperthyroidism?

You are at higher risk for hyperthyroidism if you:

• Are a woman
• Are older than age 60
• Have been pregnant or had a baby within the past 6 months
• Have had thyroid surgery or a thyroid problem, such as goiter
• Have a family history of thyroid disease
• Have pernicious anemia, in which the body cannot make enough healthy red blood cells because it does not have enough vitamin B12
• Have type 1 diabetes or primary adrenal insufficiency, a hormonal disorder
• Get too much iodine, from eating large amounts of foods containing iodine or using iodine-containing medicines or supplements

What are the symptoms of hyperthyroidism?

The symptoms of hyperthyroidism can vary from person to person and may include:

• Nervousness or irritability
• Fatigue
• Muscle weakness
• Trouble tolerating heat
• Trouble sleeping
• Tremor, usually in your hands
• Rapid and irregular heartbeat
• Frequent bowel movements or diarrhea
• Weight loss
• Mood swings
• Goiter, an enlarged thyroid that may cause your neck to look swollen. Sometimes it can cause trouble with breathing or swallowing.

Adults over age 60 may have different symptoms than younger adults. For example, they may lose their appetite or withdraw from other people. Sometimes this can be mistaken for depression or dementia.

What other problems can hyperthyroidism cause?

If hyperthyroidism isn't treated, it can cause some serious health problems, including:

• An irregular heartbeat that can lead to blood clots, stroke, heart failure, and other heart problems
• An eye disease called Graves' ophthalmopathy. It can cause double vision, light sensitivity, and eye pain. In rare cases, it can lead to vision loss.
• Thinning bones and osteoporosis
• Fertility problems in women
• Complications in pregnancy, such as premature birth, low birth weight, high blood pressure in pregnancy, and miscarriage

How is hyperthyroidism diagnosed?

Your health care provider may use many tools to make a diagnosis:

• A medical history, including asking about symptoms
• A physical exam
• Thyroid tests, such as
  • TSH, T3, T4, and thyroid antibody blood tests
  • Imaging tests, such as a thyroid scan, ultrasound, or radioactive iodine uptake test. A radioactive iodine uptake test measures how much radioactive iodine your thyroid takes up from your blood after you swallow a small amount of it.

What are the treatments for hyperthyroidism?

The treatments for hyperthyroidism include medicines, radioiodine therapy, and thyroid surgery:

• Medicines for hyperthyroidism include
  • Antithyroid medicines, which cause your thyroid to make less thyroid hormone. You probably need to take the medicines for 1 to 2 years. In some cases, you might need to take the medicines for several years. This is the simplest treatment, but it is often not a permanent cure.
  • Beta blocker medicines, which can reduce symptoms such as tremors, rapid heartbeat, and nervousness. They work quickly and can help you feel better until other treatments take effect.
• Radioiodine therapy is a common and effective treatment for hyperthyroidism. It involves taking radioactive iodine by mouth as a capsule or liquid. This slowly destroys the cells of the thyroid gland that produce thyroid hormone. It does not affect other body tissues. Almost everyone who has radioactive iodine treatment later develops hypothyroidism. This is because the thyroid hormone-producing cells have been destroyed. But hypothyroidism is easier to treat and causes fewer long-term health problems than hyperthyroidism.
• Surgery to remove part or most of the thyroid gland is done in rare cases. It might be an option for people with large goiters or pregnant women who cannot take antithyroid medicines. If you have all of your thyroid removed, you will need to take thyroid medicines for the rest of your life. Some people who have part of their thyroid removed also need to take medicines.

If you have hyperthyroidism, it's important not to get too much iodine. Talk to your health care provider about which foods, supplements, and medicines you need to avoid.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

Hypothyroidism

What is hypothyroidism?

Hypothyroidism, or underactive thyroid, happens when your thyroid gland doesn't make enough thyroid hormones to meet your body's needs.

Your thyroid is a small, butterfly-shaped gland in the front of your neck. It makes hormones that control the way the body uses energy. These hormones affect nearly every organ in your body and control many of your body's most important functions. For example, they affect your breathing, heart rate, weight, digestion, and moods. Without enough thyroid hormones, many of your body's functions slow down. But there are treatments that can help.

What causes hypothyroidism?

Hypothyroidism has several causes. They include:

• Hashimoto's disease, an autoimmune disorder where your immune system attacks your thyroid. This is the most common cause.
• Thyroiditis, inflammation of the thyroid
• Congenital hypothyroidism, hypothyroidism that is present at birth
• Surgical removal of part or all of the thyroid
• Radiation treatment of the thyroid
• Certain medicines
• In rare cases, a pituitary disease or too much or too little iodine in your diet

Who is at risk for hypothyroidism?

You are at higher risk for hypothyroidism if you:

• Are a woman
• Are older than age 60
• Have had a thyroid problem before, such as a goiter
• Have had surgery to correct a thyroid problem
• Have received radiation treatment to the thyroid, neck, or chest
• Have a family history of thyroid disease
• Were pregnant or had a baby in the past 6 months
• Have Turner syndrome, a genetic disorder that affects females
• Have pernicious anemia, in which the body cannot make enough healthy red blood cells because it does not have enough vitamin B12
• Have Sjogren's syndrome, a disease that causes dry eyes and mouth
• Have type 1 diabetes
• Have rheumatoid arthritis, an autoimmune disease that affects the joints
• Have lupus, a chronic autoimmune disease

What are the symptoms of hypothyroidism?

The symptoms of hypothyroidism can vary from person to person and may include:

• Fatigue
• Weight gain
• A puffy face
• Trouble tolerating cold
• Joint and muscle pain
• Constipation
• Dry skin
• Dry, thinning hair
• Decreased sweating
• Heavy or irregular menstrual periods
• Fertility problems in women
• Depression
• Slowed heart rate
• Goiter, an enlarged thyroid that may cause your neck to look swollen. Sometimes it can cause trouble with breathing or swallowing.

Because hypothyroidism develops slowly, many people don't notice symptoms of the disease for months or even years.

What other problems can hypothyroidism cause?

Hypothyroidism can contribute to high cholesterol. In rare cases, untreated hypothyroidism can cause myxedema coma. This is a condition in which your body's functions slow down to the point that it becomes life-threatening.

During pregnancy, hypothyroidism can cause complications, such as premature birth, high blood pressure in pregnancy, and miscarriage. It can also slow the baby's growth and development.

How is hypothyroidism diagnosed?

Your health care provider may use many tools to make a diagnosis:

• A medical history, including asking about your symptoms
• A physical exam
• Thyroid tests, such as
  • TSH, T3, T4, and thyroid antibody blood tests
  • Imaging tests, such as a thyroid scan, ultrasound, or radioactive iodine uptake test. A radioactive iodine uptake test measures how much radioactive iodine your thyroid takes up from your blood after you swallow a small amount of it.

What are the treatments for hypothyroidism?

The treatment for hypothyroidism is medicine to replace the hormone that your own thyroid can no longer make. About 6 to 8 weeks after you start taking the medicine, you will get a blood test to check your thyroid hormone level. Your health care provider will adjust your dose if needed. Each time your dose is adjusted, you'll have another blood test. Once you find the right dose, you will probably get a blood test in 6 months. After that, you will need the test once a year.

If you take your medicine according to the instructions, you usually should be able to control the hypothyroidism. You should never stop taking your medicine without talking with your health care provider first.

If you have Hashimoto's disease or other types of autoimmune thyroid disorders, you may be sensitive to harmful side effects from iodine. Talk to your health care provider about which foods, supplements, and medicines you need to avoid.

Women need more iodine when they are pregnant because the baby gets iodine from the mother's diet. If you are pregnant, talk with your health care provider about how much iodine you need.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

Kidney Diseases

You have two kidneys, each about the size of your fist. They are near the middle of your back, just below the rib cage. Inside each kidney there are about a million tiny structures called nephrons. They filter your blood. They remove wastes and extra water, which become urine. The urine flows through tubes called ureters. It goes to your bladder, which stores the urine until you go to the bathroom.

Most kidney diseases attack the nephrons. This damage may leave kidneys unable to remove wastes. Causes can include genetic problems, injuries, or medicines. You have a higher risk of kidney disease if you have diabetes, high blood pressure, or a close family member with kidney disease. Chronic kidney disease damages the nephrons slowly over several years. Other kidney problems include:

• Cancer
• Cysts
• Stones
• Infections

Your doctor can do blood and urine tests to check if you have kidney disease. If your kidneys fail, you will need dialysis or a kidney transplant.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

Kidney Tests

You have two kidneys. They are fist-sized organs on either side of your backbone above your waist. Your kidneys filter and clean your blood, taking out waste products and making urine. Kidney tests check to see how well your kidneys are working. They include blood, urine, and imaging tests.

Early kidney disease usually does not have signs or symptoms. Testing is the only way to know how your kidneys are doing. It is important for you to get checked for kidney disease if you have the key risk factors - diabetes, high blood pressure, heart disease, or a family history of kidney failure.

Specific kidney tests include:

• Glomerular filtration rate (GFR) - one of the most common blood tests to check for chronic kidney disease. It tells how well your kidneys are filtering.
• Creatinine blood and urine tests - check the levels of creatinine, a waste product that your kidneys remove from your blood
• Albumin urine test - checks for albumin, a protein that can pass into the urine if the kidneys are damaged
• Imaging tests, such as an ultrasound - provide pictures of the kidneys. The pictures help the health care provider see the size and shape of the kidneys, and check for anything unusual.
• Kidney biopsy - a procedure that involves taking a small piece of kidney tissue for examination with a microscope. It checks for the cause of kidney disease and how damaged your kidneys are.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

Low Blood Pressure

You've probably heard that high blood pressure is a problem. Sometimes blood pressure that is too low can also cause problems.

Blood pressure is the force of your blood pushing against the walls of your arteries. Each time your heart beats, it pumps out blood into the arteries. Your blood pressure is highest when your heart beats, pumping the blood. This is called systolic pressure. When your heart is at rest, between beats, your blood pressure falls. This is the diastolic pressure. Your blood pressure reading uses these two numbers. Usually they're written one above or before the other, such as 120/80. If your blood pressure reading is 90/60 or lower, you have low blood pressure.

Some people have low blood pressure all the time. They have no symptoms and their low readings are normal for them. In other people, blood pressure drops below normal because of a medical condition or certain medicines. Some people may have symptoms of low blood pressure when standing up too quickly. Low blood pressure is a problem only if it causes dizziness, fainting or in extreme cases, shock.

NIH: National Heart, Lung, and Blood Institute