Thyroid gland is one of most important glands in the body. It is located in front of the trachea (a windpipe) and secretes thyroid hormone that regulates energy storage and use. If function of that gland is decreased or there is a problem with chemicals (hormones) that are secreted, person feels tired. This condition is called hypothyroidism.
Hypothyroidism should not be confused with Hyperthyroidism, a condition when a person makes too much thyroid hormone.
People with hypothyroidism may have no symptoms, but most people feel tired. Other symptoms are cold intolerance, constipation, hair loss and skin changes. Untreated hypothyroidism causes difficulties breathing, heart weakness, swelling in feet and ankles due to fluid buildup, elevated cholesterol, disruption of monthly cycles in women and high chance of losing pregnancy.
Hypothyroidism is easily diagnosed by a blood test. Treatment involves taking thyroid hormone containing pill. Blood work should be repeated after 6 weeks to make sure that person is taking appropriate amount of thyroid hormone. There are brand names and generic medications, so it is important to do blood work after any change made. Taking too much of thyroid hormone will cause problems too.