The thyroid gland is located at the lower front of the neck. This gland takes iodine from the food you eat to make hormones called thyroxine (T4) and triiodothyronine (T3). The hormones control your metabolism (the process of turning the food you eat into energy). The thyroid gland is critical for maintaining body temperature and controlling heart rate, appetite, and digestive tract function. Too little hormone may cause you to gain weight. Also, your heartbeat slows down and your body temperature gets lower. Food moves through your intestines more slowly and your muscles contract more slowly.
How does it occur?
Causes of hypothyroidism include:
* Hashimoto's disease (thyroiditis): This condition is an inflammation of the thyroid gland. It is a disorder of your immune system (your body's protection against infection).
* Thyroid surgery for complete or partial removal of the thyroid gland
* Viruses: They can infect the thyroid gland and cause it to produce too little hormone. These infections do not usually cause permanent hypothyroidism.
* Radiation treatment for hyperthyroidism (an overactive thyroid gland): Radioactive iodine is commonly used to treat an overactive thyroid gland. Radioactivity often destroys the gland and its ability to make thyroid hormone. When this happens, the body needs synthetic thyroid hormone.
People who have had X-ray treatment for cancers of the head and neck may develop hypothyroidism if their thyroid was exposed to radiation during the cancer treatment.
* Iodine deficiency (rare): A lack of iodine in the diet is rare in the US because some foods, especially salt, contain added iodine.
* Medicines used to treat hyperthyroidism, such as lithium, or a dosage of antithyroid medicine that is too high
* Problem with the pituitary gland (rare): The pituitary gland normally stimulates the thyroid gland to produce hormones. The pituitary may fail to cause the thyroid gland to make enough hormone to meet your body's needs.
* Congenital hypothyroidism (rare): Some people are born either without thyroid glands or with glands that cannot make thyroid hormone.
Anyone can have hypothyroidism, but it happens most often in women over age 40. Some thyroid problems are inherited.
Symptoms of hypothyroidism include:
* fatigue
* depression
* muscle weakness
* constipation
* weight gain
* feeling cold a lot of the time
* heavy and prolonged menstrual periods
* coarse, dry hair
* premature graying of hair in young adults
* thick, dry skin
* swollen eyelids
* deep, hoarse voice
* thick tongue
* thickened facial features
* slowed heart rate
* decreased sexual interest
* loss of hearing
* numb and tingling hands.
A condition that develops after several years of untreated hypothyroidism is called myxedema. Myxedema can cause you to become cold, slow to talk and move, and possibly drowsy. You might even fall into a coma.
How is it diagnosed?
Your healthcare provider will ask about your symptoms and examine you. If your provider thinks that you may have hypothyroidism, you will have blood tests. The tests will measure the levels of thyroid hormone and your pituitary's thyroid-stimulating hormone (TSH). TSH causes your thyroid gland to make thyroid hormone.
How long will the effects last?
Usually hypothyroidism improves within a week after hormone therapy is begun. All symptoms go away within a few weeks. In most cases, however, you must continue this treatment for the rest of your life.
Mild hypothyroidism may cause no symptoms. If the disease progresses, however, it can become disabling over a long time if it is not treated. Untreated hypothyroidism may cause the following problems:
* enlargement of the heart and heart failure (rare)
* slowing of mental processes
* loss of consciousness.
If the cause of hypothyroidism is thyroiditis and it is not treated, your thyroid gland may swell. This swelling, called a goiter, may cause a big bulge in your neck.
How can I take care of myself? Many people with hypothyroidism, especially older adults, don't seek medical treatment because they don't know they have a problem. They may accept their symptoms of fatigue, muscle weakness, dry skin, depression, feeling cold, and constipation as signs of aging. If you notice some of the symptoms of hypothyroidism, see your healthcare provider.
When you have hypothyroidism, be sure to:
* Follow your provider's instructions for taking your medicine.
* Get your thyroid hormone level checked when your provider suggests.
* Keep your follow-up appointments.
* See you provider if your symptoms come back.
How does it occur?
Causes of hypothyroidism include:* Hashimoto's disease (thyroiditis): This condition is an inflammation of the thyroid gland. It is a disorder of your immune system (your body's protection against infection).
* Thyroid surgery for complete or partial removal of the thyroid gland
* Viruses: They can infect the thyroid gland and cause it to produce too little hormone. These infections do not usually cause permanent hypothyroidism.
* Radiation treatment for hyperthyroidism (an overactive thyroid gland): Radioactive iodine is commonly used to treat an overactive thyroid gland. Radioactivity often destroys the gland and its ability to make thyroid hormone. When this happens, the body needs synthetic thyroid hormone.
People who have had X-ray treatment for cancers of the head and neck may develop hypothyroidism if their thyroid was exposed to radiation during the cancer treatment.
* Iodine deficiency (rare): A lack of iodine in the diet is rare in the US because some foods, especially salt, contain added iodine.
* Medicines used to treat hyperthyroidism, such as lithium, or a dosage of antithyroid medicine that is too high
* Problem with the pituitary gland (rare): The pituitary gland normally stimulates the thyroid gland to produce hormones. The pituitary may fail to cause the thyroid gland to make enough hormone to meet your body's needs.
* Congenital hypothyroidism (rare): Some people are born either without thyroid glands or with glands that cannot make thyroid hormone.
Anyone can have hypothyroidism, but it happens most often in women over age 40. Some thyroid problems are inherited.
Symptoms of hypothyroidism include:
* fatigue
* depression
* muscle weakness
* constipation
* weight gain
* feeling cold a lot of the time
* heavy and prolonged menstrual periods
* coarse, dry hair
* premature graying of hair in young adults
* thick, dry skin
* swollen eyelids
* deep, hoarse voice
* thick tongue
* thickened facial features
* slowed heart rate
* decreased sexual interest
* loss of hearing
* numb and tingling hands.
A condition that develops after several years of untreated hypothyroidism is called myxedema. Myxedema can cause you to become cold, slow to talk and move, and possibly drowsy. You might even fall into a coma.
How is it diagnosed?
Your healthcare provider will ask about your symptoms and examine you. If your provider thinks that you may have hypothyroidism, you will have blood tests. The tests will measure the levels of thyroid hormone and your pituitary's thyroid-stimulating hormone (TSH). TSH causes your thyroid gland to make thyroid hormone.
How long will the effects last?
Usually hypothyroidism improves within a week after hormone therapy is begun. All symptoms go away within a few weeks. In most cases, however, you must continue this treatment for the rest of your life.
Mild hypothyroidism may cause no symptoms. If the disease progresses, however, it can become disabling over a long time if it is not treated. Untreated hypothyroidism may cause the following problems:
* enlargement of the heart and heart failure (rare)
* slowing of mental processes
* loss of consciousness.
If the cause of hypothyroidism is thyroiditis and it is not treated, your thyroid gland may swell. This swelling, called a goiter, may cause a big bulge in your neck.
How can I take care of myself? Many people with hypothyroidism, especially older adults, don't seek medical treatment because they don't know they have a problem. They may accept their symptoms of fatigue, muscle weakness, dry skin, depression, feeling cold, and constipation as signs of aging. If you notice some of the symptoms of hypothyroidism, see your healthcare provider.
When you have hypothyroidism, be sure to:
* Follow your provider's instructions for taking your medicine.
* Get your thyroid hormone level checked when your provider suggests.
* Keep your follow-up appointments.
* See you provider if your symptoms come back.