Hypothyroidism results when production of thyroid hormone by the thyroid gland falls below the body's need. Thyroid hormone controls the metabolic rate. When the body lacks sufficient thyroid hormone, the person gets tired and run down. As the body's organs slow, the person has difficulty concentrating, may gain some weight and may experience constipation, cold intolerance and other problems.
The signs and symptoms of hypothyroidism are opposite to those in hyperthyroidism since there is a deficiency of thyroid hormone secretion and all metabolic processes "slow down." The patient has poor appetite, intolerance to cold, dry, coarse, scaly, pale skin, brittle hair, tiredness, a croaky, hoarse voice, constipation and muscle weakness. Examination may reveal an absence of the thyroid gland, a thickening of the skin and underlying tissues (called myxedema), very slow reflexes and a slow heart rate. The patient can have poor memory retention. The diagnosis of hypothyroidism is confirmed by finding very low levels of thyroid hormones (T4 and T3) in the blood.
There are two fairly common causes of hypothyroidism. (1) The first is a result of previous (or currently ongoing) inflammation of the thyroid gland which leaves a large percentage of the cells of the thyroid damaged (or dead) and incapable of producing sufficient hormone. The most common cause of thyroid gland failure is called autoimmune thyroiditis (also called Hashimoto's thyroiditis), a form of thyroid inflammation caused by the patient's own immune system. (2) The second major cause is the broad category of "medical treatments". The treatment of many thyroid conditions warrants surgical removal of a portion or all of the thyroid gland. If the total mass of thyroid producing cells left within the body are not enough to meat the needs of the body, the patient will develop hypothyroidism. (3) There are several other rare causes of hypothyroidism, one of them being a completely "normal" thyroid gland which is not making enough hormone the pituitary gland does not produce enough thyroid stimulating hormone (TSH). Then the thyroid simply does not have the "signal" to make hormone.
Hypothyroidism is much more common than hyperthyroidism and may be present for many years before it is recognized. It affects approximately 2 persons in 100. The probability of having thyroid problems grows with age.
Women are three times more likely than men to have an underactive thyroid. In fact, as many as ten percent of women may have some degree of thyroid hormone deficiency.
Over five million Americans have some degree of hypothyroidism. Hashimoto's thyroiditis, an autoimmune disease that is the most common cause of hypothyroidism in the USA. This condition is characterized by inflammation and damage to the thyroid tissue.
In the 1960s, Dr. Broda Barnes proved that when thyroid function is low, the cholesterol level in the blood rises, and when thyroid hormone is administered, the level drops again.
Fibromyalgia patients benefit from thyroid treatment that includes the T3 hormone.
When hypothyroid patients are not diagnosed, or are inadequately treated with T4-only medications, the pharmaceutical companies make a fortune from the drugs prescribed to treat what are essentially hypothyroid symptoms. Abbott Labs made $541.3 million in 2000 on Synthroid alone. SSRIs are widely prescribed for depression; add in the profit the drug companies make from statins for cholesterol, pain medications for fibromyalgia, sleep aids for CFS and Fosamax for osteoporosis and the amount is staggering.