Large population studies have shown that as many as one woman in ten over the age of 65 has evidence of the earliest stages of hypothyroidism. Usually, patients with mild disease feel entirely well. However, some patients with mild hypothyroidism may note improvement in their sense of well-being after being treated with thyroid hormone. Follow-up studies show that many people with mild thyroid failure eventually develop more severe thyroid failure in later years. Therefore, such patients should be followed closely if treatment is not instituted when the problem is mild and if the patient feels well.
Hypothyroidism can occur spontaneously, or it can develop after treatment for hyperthyroidism.
Mild hypothyroidism may not cause any symptoms. With more severe hypothyroidism you may begin to feel run down, slow, depressed, sluggish, cold, tired, and may lose interest in normal daily activities. Other symptoms may include dryness and brittleness of hair, dry and itchy skin, constipation, muscle cramps, and increased menstrual flow in women. Accurate and precise diagnosis of hypothyroidism is now possible. A T4 in the low or normal range, plus a high TSH, confirms the diagnosis of thyroid failure.