If you think of the body as a motor car, the most common symptoms of hyperthyroidism imitate a vehicle that is running too fast, for too long. These symptoms include the following:
- Rapid heartbeat, sometimes with palpitations
- Extreme tiredness
- Inability to tolerate heat
- Excessive sweating
- Weight loss, with a normal or increased appetite
- Nervousness and irritability
- Inability to sleep
- Shakiness and muscle weakness, often with trembling in the hands
- Diarrhea
- Menstrual problems in women, especially lighter periods or absence of periods
Some symptoms, such as excessive sweating and the inability to tolerate a hot environment are directly due to heat generated within the body by increased metabolic activity. Weight loss reflects use of body stores of fats, proteins, and carbohydrates, as normal food intake cannot keep up with demand.
The presence and severity of symptoms varies from person to person. For reasons not understood, older individuals with hyperthyroidism often have far fewe symptoms compared to younger people. Although many symptoms of hyperthyroidism cause distress, most are not dangerous. An exception occurs in some people who have heart disease. In these cases, untreated hyperthyroidism places additional stress on the heart, causing problems such as heart failure, irregular heartbeat (atrial fibrillation), or abnormal heart rhythm (arrythmia).
For further information about heart failure, go to Heart Failure.
For further information about palpitations, go to Palpitations.
