A nurse is caring for a client who has headaches. In determining a diagnosis, which of the following precipitating factors is common in both tension-type headaches and cluster headaches?

Rationale: A. Depression is incorrect because, although depression is often associated with tension-type headaches, it is not a recognized precipitating factor for cluster headaches, which are more episodic and related to hypothalamic and vascular triggers. B. Smoking is incorrect because smoking is a known risk factor for cluster headaches but is not commonly associated with tension-type headaches. C. Poor posture is incorrect because poor posture contributes mainly to tension-type headaches due to muscle strain and cervical tension, but it does not typically precipitate cluster headaches. D. Stress is correct because it is a common precipitating factor for both tension-type headaches and cluster headaches. Stress can trigger muscle tension leading to tension headaches and can also act as a trigger for cluster headache episodes, likely through neurovascular mechanisms and hypothalamic involvement.