头疼可能由多种原因引起，包括偏头痛、紧张型头痛、感冒、月经痛、应激等。如果头疼严重或持续不断，建议寻求医生的帮助，以确定可能的原因并找到适当的治疗方法 [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]。
[1]头痛和偏头痛：缺勤的主要原因。[PubMed:Headache and migraine: a leading cause of absenteeism.(2016)]
[2]儿童头痛的继发性颅内原因。[PubMed:Secondary intracranial causes for headaches in children.(2009)]
[3]以头痛为唯一症状的疾病。[PubMed:Disorders presenting with headache as the sole symptom.(2010)]
[4]应激性头痛的中枢机制。[PubMed:Central mechanisms of stress-induced headache.(2011)]
[5]可归因于传染病的头痛。[PubMed:Headaches attributable to infectious diseases.(2011)]
[6]与风湿病有关的头痛。[PubMed:Headaches related to rheumatologic disease.(2014)]
[7]原发性头痛。[PubMed:Primary Headaches.(2019)]
[8]老年人头痛。他们在这个年龄段有什么不同？[PubMed:Headaches in older people. How are they different in this age-group?(1997)]
[9]普通感冒[PubMed:Common Cold(2023)]
[10]经前期综合征[PubMed:Premenstrual Syndrome(2023)]
[11]经期疼痛[PubMed:Period Pain(2023)]
[12]发作性偏头痛的触发因素，保护因素和预测因素。[PubMed:Triggers, Protectors, and Predictors in Episodic Migraine.(2019)]