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?

Choice A reason: Depression may be associated with chronic tension-type headaches but is not a common precipitating factor for cluster headaches. Choice B reason: Poor posture is a known trigger for tension-type headaches due to muscle strain but is not linked to cluster headaches. Choice C reason: Stress is a common precipitating factor for both tension-type and cluster headaches. It can trigger muscle tension and neurovascular changes that lead to headache onset. Choice D reason: Smoking is more strongly associated with cluster headaches but not typically with tension-type headaches.