Patients with Graves' disease may experience many of the symptoms of hyperthyroidism, including anxiety and irritability. They may have trouble sleeping and may experience fatigue and unexplained weight loss, despite eating normally or excessively (polyphagia).

Other symptoms may include:

• Changes in bowel patterns. In particular, patients are more likely to have increased frequency of bowel movements.
  
  
• Changes to appearance. Patients may experience thinning of the skin and may develop fine, brittle hair.
  
  
• Enlarged thyroid gland. Also known as goiter, this can be felt or even seen as a swelling at the base of the neck.
  
  
• Increased sweating. Some patients also may experience increased sensitivity to heat.
  
  
• Irregular or rapid heartbeat. Patients may experience irregular heartbeat (arrhythmia) and palpitations. They also may experience rapid heartbeat of more than 100 beats per minute.
  
  
• Irritability. Patients sometimes experience anxiety attacks.
  
  
• Tremor. Most often, this appears as a fine trembling in the hands or fingers.
  
  
• Irregular menstruation. Women may experience light or absent periods.

Graves' disease is the only source of hyperthyroidism that can cause swelling of tissues behind the eyes. This is known as Graves' ophthalmopathy, and its symptoms may include:

• Blurry or double vision
  
• Bulging eyes beyond the protective socket
  
• Dryness on the eye surface
  
• Excessive tearing or discomfort
  
• Inflammation
  
• Red or swollen eyes
  
• Reduced eye movement
  
• Sensation of grit or sand in the eyes
  
• Sensitivity to light
  
• Widening of space between eyelids

Less frequently, patients with Graves' ophthalmopathy may experience more severe symptoms. These may include ulcers on the cornea of the eye, double vision, limitations on eye movement, and blurred or reduced vision.

Graves' disease also may cause a lumpy, reddish thickening on the skin in front of the shins and on the top of the feet. This is known as Graves' dermopathy or pretibial myxedema. In most cases, this skin condition does not cause pain.