Hyperthyroidism is a condition in which the thyroid gland produces too much of the hormone thyroxine. Merck Manuals, an online medical library, reports that hyperthyroidism most commonly affects women after childbirth or menopause, but hyperthyroidism can affect men as well. Hyperthyroidism may also be caused by an autoimmune disease called Graves' disease, thyroiditis (inflammation of the thyroid), or exposure to certain toxic chemicals or radiation.
MedlinePlus, an online medical encyclopedia provided by the U.S. Department of Health and Human Services, reports that there are multiple common symptoms of hyperthyroidism in men. These symptoms include fatigue, changes in appetite, increased sweating, restlessness, intolerance of heat, difficulty concentrating, and weight loss. Another common symptom of hyperthyroidism is the development of a goiter, which is a swelling a the base of the neck due to an enlarged thyroid. According to Merck Manuals, the whole thyroid may be enlarged, or parts of it may be enlarged, forming hard protruding nodules.
Less Common Symptoms
Other symptoms of hyperthyroidism in men include clammy skin, hair loss, hand tremors, diarrhea, vomiting, nausea and weakness. There also may be changes in heartbeat. The heart rate may become faster or irregular, and may feel particularly forceful or pounding. Blood pressure may also increase.
A common cause of hyperthyroidism, as mentioned above, is an autoimmune disease called Graves' disease. In Graves' disease, the immune system attacks and stimulates the thyroid, causing it to produce too much thyroxine. A sign that Grave's disease may be the cause of hyperthyroidism is the development of symptoms that affect the eyes. These symptoms include, according to Merck Manuals, puffiness around the eyes; protruding/bulging eyes; excessive eye irritation; an overproduction of tears.
According to MedlinePlus, one symptom of hyperthyroidism that affects only men is the abnormal development of breasts, which is technically called gynecomastia. The Mayo Clinic reports that gynecomastia is characterized by swelling of the breast tissue. In and of itself, gynecomastia is not a serious physical problem, though may be difficult for men to deal with. Following treatment with medication to reduce the body's thyroxine levels, the breast enlargement in men is usually reversed.