What condition may cause symptoms like rapid heartbeat and anxiety?

Hyperthyroidism is characterized by an overproduction of thyroid hormones, which can significantly affect the body's metabolism. This increased hormone level leads to several physiological changes, including heightened heart rate, also known as tachycardia, and symptoms of anxiety. In hyperthyroidism, the excessive amount of thyroid hormone stimulates many body systems, increasing the metabolic rate and leading to symptoms like rapid heartbeat, restlessness, nervousness, and irritability.

The symptoms of anxiety and rapid heartbeat are directly linked to the overactivity of the sympathetic nervous system, which is one of the reasons individuals with hyperthyroidism often report feeling jittery or anxious. Additionally, other symptoms can include weight loss, heat intolerance, tremors, and increased sweating, further illustrating the systemic impact of this condition.

When examining the other options, hypoglycemia can also cause rapid heartbeat and anxiety due to the body's response to low blood sugar, but hyperthyroidism is more specifically associated with persistent symptoms from thyroid hormone elevation. Adrenal insufficiency typically leads to fatigue and weakness rather than rapid heartbeat and anxiety. Diabetes insipidus is primarily characterized by increased thirst and urination without a direct impact on heart rate or anxiety levels. Thus, hyperthyroidism is the most fitting condition that explains