Hypothyroidism

What is hypothyroidism?

The thyroid is a gland in the front of your neck, located just below your Adam's apple. Hypothyroidism, or low thyroid activity (also called myxedema), is a fairly widespread condition in which the body lacks an adequate supply of the thyroid hormone. The main function of the thyroid hormone is to regulate the body's metabolism and therefore people with this condition will have symptoms associated with a slow metabolism.

Causes of hypothyroidism

• Hypothyroidism may be caused by inadequate production of thyroid hormone, usually after surgical removal of the thyroid (thyroidectomy) or radiation therapy of the thyroid (e.g. for hyperthyroidism), inflammation, chronic auto-immune thyroiditis or conditions such as amyloidosis and acidosis.

• Hypothyroidism may be caused by pituitary failure to produce thyroid-stimulating hormone, or failure of the hypothalamus (an area in the brain that stimulates the pituitary) to produce thyroid-releasing hormone, inborn errors of thyroid hormone manufacturing by the body, iodine deficiency or use of anti-thyroid medication such as propylthiouracil.

• 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 jeopardise the health of both mother and baby.

• 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.

You have an increased risk of developing hypothyroidism if:

• you have a close relative with an auto-immune disease;
• you have been treated with radioactive iodine or anti-thyroid medication; and
• you have received radiation therapy to your neck or upper chest.

Symptoms of hypothyroidism

Most people will have a combination of these symptoms and they may differ greatly from one individual to another:

• fatigue;
• weakness;
• weight gain or increased difficulty losing weight;
• coarse, dry hair;
• dry, rough pale skin;
• hair loss;
• cold intolerance (can't tolerate the cold like other persons around you);
• muscle cramps and frequent muscle aches;
• constipation;
• depression;
• Irritability;
• memory loss;
• abnormal menstrual cycles; and
• decreased libido (reduced sexual desire).

Occasionally, some patients with hypothyroidism may have no symptoms at all, or they are just so subtle that they go unnoticed.

Dangers of hypothyroidism

Advanced hypothyroidism, called ‘myxedema crisis', is rare and can be severe. Symptoms of myxedema crisis could include low blood pressure, decreased breathing, decreased body temperature, unresponsiveness, and even a coma.

If hypothyroidism is not treated, it can lead to other health problems:

• it can cause your thyroid to become larger, creating a swollen lump on your neck called a goitre;
• an increased risk of heart disease because an under-active thyroid causes high levels of ‘bad' cholesterol;
• mental health conditions like depression; and
• babies born to women with untreated hypothyroidism may have birth defects.

Treatment of hypothyroidism

Even though hypothyroidism is completely treatable in many patients simply by taking a small pill daily, one type of medication will not necessarily be the best therapy for all patients. Many factors are evaluated during treatment and it could differ from person to person.

If you have symptoms of an under-active 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, pregnant women or women who are planning pregnancy for hypothyroidism during routine physical examinations.

The typical treatment for an under-active thyroid is synthetic thyroid hormone in tablet form. This medication will return regular hormone levels and change your metabolism back to normal. It will also lower your cholesterol and may assist with weight loss.

Your doctor can tell by how you are feeling, by examination and by blood tests if you are on the right dose of thyroid hormone.

References

http://www.endocrineweb.com

http://familydoctor.org