Symptoms

Hyperthyroidism can mimic other health problems, which can make it difficult for your doctor to diagnose. It can also cause a wide variety of signs and symptoms, including:

• Unintentional weight loss, even when your appetite and food intake stay the same or increase
• Rapid heartbeat (tachycardia) — commonly more than 100 beats a minute
• Irregular heartbeat (arrhythmia)
• Pounding of your heart (palpitations)
• Increased appetite
• Nervousness, anxiety and irritability
• Tremor — usually a fine trembling in your hands and fingers
• Sweating
• 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.

Graves' ophthalmopathy

Sometimes an uncommon problem called Graves' ophthalmopathy may affect your eyes, especially if you smoke. This disorder makes your eyeballs protrude beyond their normal protective orbits when the tissues and muscles behind your eyes swell. Eye problems often improve without treatment.

Signs and symptoms of Graves' ophthalmopathy include:

• Dry eyes
• Red or swollen eyes
• Excessive tearing or discomfort in one or both eyes
• Light sensitivity, blurry or double vision, inflammation, or reduced eye movement
• Protruding eyeballs

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 signs and 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 you currently are being treated, see your doctor regularly as advised so that he or she can monitor your condition.