Which of the following is NOT a symptom of hyperthyroid?

Weight gain is indeed not a symptom of hyperthyroidism. In fact, hyperthyroidism typically leads to weight loss due to an increased metabolic rate, which results in the body burning energy more rapidly than usual. This increased metabolism often manifests as symptoms like tremors, irritability, and heat sensitivity.

Tremors are common as the heightened levels of thyroid hormones can stimulate the nervous system, leading to shakiness. Irritability also arises from the increased energy and metabolic changes that can affect mood and anxiety levels. Heat sensitivity occurs because individuals with hyperthyroidism often struggle to regulate their body temperature effectively, feeling excessively warm. Hence, weight gain is inconsistent with the clinical presentation of hyperthyroidism, marking it clearly different from the other symptoms listed.