Headaches and academic performance in university students: a cross-sectional study. 
To estimate the 1-year prevalence of headache, its repercussion and its association with the academic performance of university students.  Cross-sectional study.  Three hundred eighty students were randomly selected out of the 1718, 90.5% of them were interviewed.  A semi-structured interview, the Headache Impact Test (HIT-6) and the Hospital Anxiety and Depression Scale were used.  The variables related to academic performance: absenteeism, performance coefficient and number of failures in disciplines, were obtained by consulting the academic records.  Three hundred forty-four students were interviewed.  The headache prevalence was 87.2%.  Migraine prevalence was 48.5%.  Tension-type headache prevalence was 42.4%.  During the 3 months prior to the interview, 8.7% sought emergency services, 30.8% missed class, and 30.8% had a reduction in their productive capacity because of headache.  HIT-6: substantial/severe impact = 49%.  Multiple linear regressions have shown that serious/very serious-impact headaches are significantly related to greater number of discipline failure and absenteeism.  There was no association between student grades and headaches.  A high prevalence of headache in the studied population was verified.  A high headache impact on a student's life was associated with worse academic performance.