By Mayo Clinic staff
Hyperthyroidism (overactive thyroid) is a condition in which your thyroid gland produces too much of the hormone thyroxine. Hyperthyroidism can accelerate your body's metabolism significantly, causing sudden weight loss, a rapid or irregular heartbeat, sweating, and nervousness or irritability.
Several treatment options are available if you have hyperthyroidism. Doctors use anti-thyroid medications and radioactive iodine to slow the production of thyroid hormones. Sometimes, treatment of hyperthyroidism involves surgery to remove all or part of your thyroid gland. Although hyperthyroidism can be serious if you ignore it, most people respond well once hyperthyroidism is diagnosed and treated.
By Mayo Clinic staff
Hyperthyroidism can mimic other health problems, which may make it difficult for your doctor to diagnose. It can also cause a wide variety of signs and symptoms, including:
- Sudden weight loss, even when your appetite and the amount and type of food you eat remain the same or even increase
- Rapid heartbeat (tachycardia) — commonly more than 100 beats a minute — irregular heartbeat (arrhythmia) or pounding of your heart (palpitations)
- Increased appetite
- Nervousness, anxiety and irritability
- Tremor — usually a fine trembling in your hands and fingers
- Changes in menstrual patterns
- Increased sensitivity to heat
- Changes in bowel patterns, especially more frequent bowel movements
- An enlarged thyroid gland (goiter), which may appear as a swelling at the base of your neck
- Fatigue, muscle weakness
- Difficulty sleeping
- Skin thinning
- Fine, brittle hair
Older adults are more likely to have either no signs or symptoms or subtle ones, such as an increased heart rate, heat intolerance and a tendency to become tired during ordinary activities. Medications called beta blockers, which are used to treat high blood pressure and other conditions, can mask many of the signs of hyperthyroidism.
Sometimes an uncommon problem called Graves' ophthalmopathy may affect your eyes, especially if you smoke. In this disorder, your eyeballs protrude beyond their normal protective orbits when the tissues and muscles behind your eyes swell. This pushes the eyeballs forward so far that they actually bulge out of their orbits. This can cause the front surface of your eyeballs to become very dry. Eye problems often improve without treatment.
Signs and symptoms of Graves' ophthalmopathy include:
- Protruding eyeballs
- Red or swollen eyes
- Excessive tearing or discomfort in one or both eyes
- Light sensitivity, blurry or double vision, inflammation, or reduced eye movement
When to see a doctor
If you experience unexplained weight loss, a rapid heartbeat, unusual sweating, swelling at the base of your neck or other symptoms associated with hyperthyroidism, see your doctor. It's important to completely describe the changes you've observed, because many signs and symptoms of hyperthyroidism may be associated with a number of other conditions.
If you've been treated for hyperthyroidism or currently are being treated, see your doctor regularly as advised so that he or she can monitor your condition.