Hypothyroidism

The thyroid gland performs a vital function: It produces the hormones that regulate the metabolism. Thyroid hormones direct many of the body’s processes.

An underactive thyroid does not produce enough hormones. This condition is also referred to as hypothyroidism. This can lead to various problems: It slows down the metabolism, which may cause fatigue, lethargy, or constipation.

Chronic inflammation of the thyroid gland is the most common cause of an underactive thyroid. It can be treated easily by taking a tablet containing the thyroid hormone once a day. Once the hormone has been replaced the symptoms usually disappear.

The symptoms of hypothyroidism usually develop slowly over time – sometimes years. They can include:

Feeling tired (fatigue).

Experiencing numbness and tingling in your hands.

Having constipation.

Gaining weight.

Experiencing soreness throughout your body (can include muscle weakness).

Having higher than normal blood cholesterol levels.

Feeling depressed.

Being unable to tolerate cold temperatures.

Having dry, coarse skin and hair.

Experiencing a decrease sexual interest.

Having frequent and heavy menstrual periods.

Seeing physical changes in your face (including drooping eyelids, as well as puffiness in the eyes and face).

Having your voice become lower and hoarser.

Feeling more forgetful (“brain fog”).

Hypothyroidism can have a primary cause or a secondary cause. A primary cause is a condition that directly impacts the thyroid and causes it to create low levels of thyroid hormones. A secondary cause is something that causes the pituitary gland to fail, which means it can’t send thyroid stimulating hormone (TSH) to the thyroid to balance out the thyroid hormones.

Primary causes of hypothyroidism are much more common. The most common of these primary causes is an autoimmune condition called Hashimoto’s disease. Also called Hashimoto’s thyroiditis or chronic lymphocytic thyroiditis, this condition is hereditary (passed down through a family). In Hashimoto’s disease, the body’s immune system attacks and damages the thyroid. This prevents the thyroid from making and releasing enough thyroid hormone.

The other primary causes of hypothyroidism can include:

Thyroiditis (inflammation of the thyroid).

Treatment of hyperthyroidism (radiation and surgical removal of the thyroid).

Iodine deficiency (not having enough iodine — a mineral your thyroid uses to make hormones – in your body).

Hereditary conditions (a medical condition passed down through your family).

In some cases, thyroiditis can happen after a pregnancy (postpartum thyroiditis) or a viral illness.

Causes hypothyroidism in pregnancy

In most cases, women with hypothyroidism during pregnancy have Hashimoto’s disease. This autoimmune disease causes the body’s immune system to attack and damage the thyroid. When that happens, the thyroid can’t produce and release high enough levels of thyroid hormones, impacting the entire body. Pregnant women with hypothyroidism may feel very tired, have a hard time dealing with cold temperatures and experience muscles cramps.

Thyroid hormones are important to your baby’s development while in the womb. These hormones help develop the brain and nervous system. If you have hypothyroidism, it’s important to control your thyroid levels during pregnancy. If your baby doesn’t get enough thyroid hormone during development, the brain may not develop correctly and there could be issues later. Untreated or insufficiently treated hypothyroidism during pregnancy may lead to complications like miscarriage or preterm labor.

Less often, hypothyroidism may result from one of the following:

Congenital disease. Some babies are born with a defective thyroid gland or no thyroid gland. ...

Pituitary disorder. ...

Pregnancy. ...

Iodine deficiency.

Are a woman.

Are older than 60.

Have a family history of thyroid disease.

Have an autoimmune disease, such as type 1 diabetes or celiac disease.

Have been treated with radioactive iodine or anti-thyroid medications.

Received radiation to your neck or upper chest.

Have had thyroid surgery (partial thyroidectomy)

Goiter. Constant stimulation of your thyroid to release more hormones may cause the gland to become larger — a condition known as a goiter. ...

Heart problems. ...

Mental health issues. ...

Peripheral neuropathy. ...

Myxedema. ...

Infertility. ...

Birth defects.

Hypothyroidism cannot be prevented. The best way to prevent developing a serious form of the condition or having the symptoms impact your life in a serious way is to watch for signs of hypothyroidism. If you experience any of the symptoms of hypothyroidism, the best thing to do is talk to your healthcare provider.

There is no way to prevent hypothyroidism, but people who may have a higher risk of thyroid problems, for example, women during pregnancy, should check with their doctor about the need for additional iodine.