Onset, Triggers, Imaging and Medication in the Headache History

New headache after fifty is usually secondary. A thunderclap onset peaking within five minutes is a major red flag: CT is highly reliable early but drops to about 50% accuracy within a week. About a third of new headaches in pregnancy are significant, and headache that starts with exertion is secondary until proven otherwise. Minor trauma in older patients on anticoagulants can lead to a slowly expanding subdural hematoma. Alastair lists migraine triggers including diet, dehydration, missed meals, stress, sleep, neck and jaw pain, illness and hormones. Poor sleep is an independent risk factor for headache becoming chronic. Imaging is needed for thunderclap or exertional onset, trauma, focal neurological signs, new headache in pregnancy, strong postural change or escalating headache. Medication overuse headache is a risk with simple analgesics on more than 15 days a month, opioids or triptans on 10 or more days, or more than about three espressos a day. Preventive migraine drugs often need low starting doses titrated slowly.