Because symptoms generally come on gradually over weeks or months, you may have hyperthyroidism for a long time before you realize it. If you are an older adult, it may be even harder to recognize that something is wrong, because your only symptoms may be weight loss and/or depression.

Symptoms vary so greatly from individual to individual, you may have one, more than one, all, or none of the following symptoms. There are many symptoms of hyperthyroidism. These may include:

• Restlessness, nervousness, and irritability
• Fatigue and weakness may follow the restlessness and nervousness
• Heat intolerance
• Heart palpitations, irregular heartbeat, skipped beats
• Tachycardia —Rapid heartbeat and pulse.
• Unexplained weight loss—An increased metabolism means your body is burning calories more rapidly, thus you may lose weight even though you are eating more. However, 5%-10% of people with hyperthyroidism gain weight because they are eating more.
• Warm, moist skin
• Increased bowel movements—Food travels more quickly through the gastrointestinal tract.
• Insomnia—You may have trouble sleeping in spite of the fact that you feel tired all the time.
• Tremor—If you stretch out your fingers, you may have a fine tremor.
• Menstrual irregularity
• Loss of libido
• Fine hair texture—Up to 40% of patients experience some baldness. This can last for months after the thyroid hormone level has been restored to normal
• Bulging eyes (called exophthalmos)—This can occur in Graves disease.
• Shortness of breath—This may occur when the hyperthyroidism is severe and the heart rate is rapid or there is an irregular pulse. Severe hyperthyroidism can result in heart failure.
• Swelling in legs

In individuals over age 65 years, hyperthyroidism may present with the following:

• Heart failure
• Atrial fibrillation
• No appetite
• Muscle wasting
• Depression
• Forgetfulness