What symptom noted in Nevaeh's assessment is indicative of anxiety and hyperthyroidism?

Tremors are a clinical symptom closely associated with both anxiety and hyperthyroidism. In hyperthyroidism, the excess thyroid hormones increase metabolism and can lead to muscle hyperactivity, which manifests as tremors or fine shaking, particularly in the hands. This symptom is a reflection of the body's heightened state of adrenergic activity, often accompanied by other signs such as increased heart rate and anxiety.

In the context of anxiety, tremors can also occur as a physical response to stress and nervousness, as the body's fight-or-flight response can activate trembling. This shared symptom between the two conditions makes it a clear indicator of both anxiety and hyperthyroidism.

Other symptoms listed, such as chronic headaches, weight gain, and increased appetite, do not align as closely with hyperthyroidism. In fact, hyperthyroidism typically presents with weight loss and increased appetite, while chronic headaches may be less directly linked to the thyroid's activity and more related to other factors. Consequently, tremors serve as a distinctive sign that can be associated with the physiological changes occurring in both anxiety and hyperthyroidism.