Hyperthyroidism sometimes looks like other health problems. That can make it hard to diagnose. It can cause many symptoms, including: 
Losing weight without trying.
Fast heartbeat, a condition called tachycardia.
Irregular heartbeat, also called arrhythmia.
Pounding of the heart, sometimes called heart palpitations.
Increased hunger.
Nervousness, anxiety and irritability.
Tremor, usually a small trembling in the hands and fingers.
Sweating.
Changes in menstrual cycles.
Increased sensitivity to heat.
Changes in bowel patterns, especially more-frequent bowel movements.
Enlarged thyroid gland, sometimes called a goiter, which may appear as a swelling at the base of the neck.
Tiredness.
Muscle weakness.
Sleep problems.
Warm, moist skin.
Thinning skin.
Fine, brittle hair.
 Older adults are more likely to have symptoms that are hard to notice. These symptoms may include an irregular heartbeat, weight loss, depression, and feeling weak or tired during ordinary activities.