Which symptom is most commonly associated with hyperthyroidism?

Hyperthyroidism is characterized by an overproduction of thyroid hormones, which can significantly increase the body's metabolic rate. This heightened metabolic activity often manifests in a variety of symptoms, with tremors being one of the most typical manifestations. The increased levels of thyroid hormones stimulate the nervous system, leading to heightened muscle activity and tremors, particularly in the hands.

The symptoms associated with hyperthyroidism generally include increased heart rate, weight loss despite increased appetite, heat intolerance, and nervousness or anxiety, alongside tremors. These tremors are often fine and may be noticeable during specific activities or at rest.

In contrast, the other options present symptoms that are not predominantly associated with hyperthyroidism. Weight gain, for instance, is more commonly connected to hypothyroidism, where there is a decrease in hormone production leading to slowed metabolism. Cold intolerance also aligns more with an underactive thyroid. Fatigue can be seen in both conditions, but it is not as specific to hyperthyroidism as the presence of tremors, making tremors a hallmark symptom of this condition.