The thyroid gland is a small gland located in the neck, shaped like a butterfly. It's responsible for producing certain hormones -- chemical "messengers" that help regulate normal body function -- called thyroid hormones. As described in the National Institutes of Health website, MedlinePlus, certain conditions or diseases can cause the thyroid to become overactive and produce excessive amounts of thyroid hormones. This is called hyperthyroidism. The opposite extreme, in which inadequate amounts of thyroid hormones are produced, may also occur -- hypothyroidism. Both conditions may cause problems in maintaining a healthy weight.
Hypothyroidism
The National Institute of Diabetes and Digestive and Kidney Diseases, or NIDDK, defines hypothyroidism in a straightforward way: the situation that arises when too little thyroid hormone is produced to adequately meet the body's needs. Although several conditions can result in the development of hypothyroidism, the most common cause is a disease called Hashimoto's thyroiditis. This disease is autoimmune, which means the body's immune system incorrectly recognizes the cells of the thyroid as "foreign" and attacks them. The damaged thyroid cells are unable to produce thyroid hormones and a variety of symptoms ensue, reflecting the fact that the body's metabolism slows down without enough thyroid hormone. Common symptoms include fatigue and cold intolerance; another problematic symptom is weight gain or an inability to lose weight despite regular exercise and a healthy diet. Patients who notice unintended weight gain, or who are unable to lose weight -- especially if other symptoms are present -- may consider being tested for hypothyroidism. It's diagnosed with a blood test and can be treated quite easily, by taking synthetic thyroid hormone as a pill.
Hyperthyroidism
In hyperthyroidism, too much thyroid hormone is being produced. This can occur for several reasons. MedlinePlus lists causes such as too much iodine in the diet; thyroid inflammation due to viral illness; benign, noncancerous tumors that arise either in the thyroid or pituitary glands; and an autoimmune disease called Graves' disease. Regardless of specific cause, hyperthyroidism results in a sped-up metabolism, leading to symptoms such as excessive perspiration, heat intolerance, rapid heartbeat and anxiety. For some patients, the issue of weight loss becomes serious: They lose weight despite having an unusually large appetite. Though weight loss may seem like a desirable symptom, for some people -- for example, people with other medical conditions, patients who have eating disorders or digestive diseases, or people who are especially active -- being unable to maintain a healthy weight can be a significant problem, even dangerous. Patients experiencing symptoms consistent with hyperthyroidism should contact their health care provider for testing and treatment.
Diet and Exercise
Patients who suffer from thyroid conditions -- either the slowed-down metabolism of hypothyroidism or the increased metabolism of hyperthyroidism -- should pay close attention to the food and drink they consume, as well as the amount of exercise they get. As MedlinePlus reminds readers, the keys to successfully losing weight and maintaining a healthy weight are to exercise consistently -- at least three sessions weekly of 20-minute aerobic exercise -- and a balanced diet that's low in fat and sugar. For patients who are frustrated by their hypothyroidism, making these healthy lifestyle choices may help deal with the unintended weight gain associated with this condition. For patients experiencing hyperthyroid weight-loss symptoms, well-balanced meals may be especially important.
