Hypothyroidism, or low thyroid activity, means your body is not making enough thyroid hormone. The thyroid is a gland in the front of your neck, located just below your Adam’s apple. It makes hormones that control metabolism, the pace of your body’s processes. Metabolism includes things like your heart rate and how quickly you burn calories. Women, especially those over 50, are more likely to have hypothyroidism than men are. Hypothyroidism can cause obesity, joint pain, infertility and heart disease.
Hypothyroidism
What is hypothyroidism?
What causes hypothyroidism?
The most common cause of hypothyroidism is an autoimmune disease called Hashimoto’s thyroiditis. Normally, antibodies produced by the immune system help protect the body against viruses, bacteria and other foreign substances. With Hashimoto’s thyroiditis, antibodies attack the thyroid and keep it from producing enough hormone.
Other common causes of hypothyroidism:
Other common causes of hypothyroidism:
- treatment for hyperthyroidism, the condition in which the body produces too much thyroid hormone;
- radiation therapy;
- thyroid surgery, or
- certain medications.
Some less common causes of hypothyroidism:
- Congenital disease: About 1 in 3,000 infants are born with a defective thyroid or no thyroid at all. Most states require doctors to screen newborns for thyroid problems.
- Pituitary disorder: The pituitary gland produces thyroid-stimulating hormone, which tells the thyroid gland how much thyroid hormone to produce. A pituitary disorder may keep the pituitary gland from producing the right amount of thyroid-stimulating hormone.
- Pregnancy: Some women develop hypothyroidism during or after pregnancy because their bodies produce antibodies that attack the thyroid gland. If it is not treated, hypothyroidism can jeopardize the health of both mother and baby.
- Iodine deficiency: Iodine is a trace mineral used by the body to make thyroid hormones. In some parts of the world, iodine deficiency keeps the body from being able to make enough thyroid hormone. In the United States, table salt has iodine added to it to make sure everyone gets enough.
You have an increased risk of developing hypothyroidism if you:
- have a close relative with an autoimmune disease,
- have been treated with radioactive iodine or anti-thyroid medications,
- have received radiation therapy to your neck or upper chest, or
- have had thyroid surgery.
What are the symptoms of hypothyroidism?
The symptoms of hypothyroidism tend to develop slowly. They can be different from case to case. Initial symptoms include slight fatigue and sluggishness. As your metabolism slows, you may develop other symptoms:
- Increased sensitivity to cold
- Constipation
- Pale, dry skin and hair
- Puffy face
- Hoarse voice
- Elevated blood cholesterol
- Unexpected weight gain
- Constipation
- Muscle aches, cramps, tenderness or stiffness
- Pain, stiffness or swelling in your joints
- Heavier-than-normal menstrual periods
- Depression, forgetfulness
- Visibly enlarged thyroid
Advanced hypothyroidism, called myxedema, is rare and can be life-threatening. Symptoms include low blood pressure, decreased breathing, decreased body temperature, unresponsiveness, and even coma.
Can children have hypothyroidism?
Anyone can develop the condition, including infants and teenagers.
Babies born without a thyroid gland or with a thyroid that doesn’t work properly don’t have many symptoms at first. They may have yellowing of the skin and the whites of their eyes (jaundice), frequent choking, and a large tongue that sticks out slightly. As the disease progresses, infants may have trouble feeding and may not grow and develop normally. They may also be constipated, have poor muscle tone or be very sleepy. If it is not treated, hypothyroidism in infants can lead to physical and mental retardation. In the United States, newborn infants are screened for hypothyroidism before leaving the hospital.
Children and teens who develop hypothyroidism have the same symptoms as adults, but they may also experience:
Babies born without a thyroid gland or with a thyroid that doesn’t work properly don’t have many symptoms at first. They may have yellowing of the skin and the whites of their eyes (jaundice), frequent choking, and a large tongue that sticks out slightly. As the disease progresses, infants may have trouble feeding and may not grow and develop normally. They may also be constipated, have poor muscle tone or be very sleepy. If it is not treated, hypothyroidism in infants can lead to physical and mental retardation. In the United States, newborn infants are screened for hypothyroidism before leaving the hospital.
Children and teens who develop hypothyroidism have the same symptoms as adults, but they may also experience:
- Poor growth
- Delayed development of permanent teeth
- Delayed puberty
- Poor mental development
How will my doctor know I have hypothyroidism?
If you have symptoms of an underactive thyroid, your doctor will do tests that measure the levels of thyroid hormone and thyroid-stimulating hormone in your blood.
Some doctors recommend screening older women for hypothyroidism during routine physical examinations. Some also recommend screening pregnant women and women who are thinking about becoming pregnant.
Some doctors recommend screening older women for hypothyroidism during routine physical examinations. Some also recommend screening pregnant women and women who are thinking about becoming pregnant.
Are there any complications I should know about?
If it is not treated, hypothyroidism can lead to other health problems:
- Goiter: Hypothyroidism can cause your thyroid to become larger, creating a swollen lump on your neck called a goiter. A goiter can affect your appearance and can even make it harder for you to swallow or eat.
- An increased risk of heart disease: An underactive thyroid causes high levels of “bad” cholesterol.
- Mental health issues like depression.
- Myxedema: A rare, life-threatening condition characterized by intense sensitivity to cold, drowsiness followed by severe sluggishness, leading to unconsciousness and coma.
- Birth defects: Babies born to women with untreated hypothyroidism may have birth defects.
How is hypothyroidism treated?
The standard treatment for an underactive thyroid is synthetic thyroid hormone. This medication will restore hormone levels and shift your metabolism back to normal. It will also lower your cholesterol and may help reverse weight gain. It may take a few tries to get the right dose of synthetic thyroid hormone. If you are not taking enough, you may continue to have symptoms of hypothyroidism. If you are taking too much, you may have symptoms similar to those of hyperthyroidism (overactive thyroid disease). Your doctor can tell by how you feel, by examination, and by blood testing if you are on the right dose of thyroid hormone.
Some medications, supplements and foods may affect your body’s ability to absorb the synthetic thyroid hormone. Tell your doctor if you eat large amounts of soy products, are on a high-fiber diet, or take other medications like iron supplements, cholestyramine, or aluminum hydroxide (in some antacids).
Some medications, supplements and foods may affect your body’s ability to absorb the synthetic thyroid hormone. Tell your doctor if you eat large amounts of soy products, are on a high-fiber diet, or take other medications like iron supplements, cholestyramine, or aluminum hydroxide (in some antacids).
Source
Written by familydoctor.org editorial staff.
American Academy of Family Physicians
Created: 09/07