BACKGROUND: Many women with heavy periods and irregular bleeding do not consult about them. It has been suggested that some of these symptoms are associated with psychological distress and that this influences consultation behaviour which may account for why some women present with a menstrual disturbance and others with apparently the same problem do not. AIM: To explore the relationship between symptom severity, psychological distress, and the seeking of medical help in primary care among women aged 54 years or less with increased vaginal bleeding. DESIGN OF STUDY: Case control. SETTING: An urban four-partner general practice of 10,000 patients. METHOD: Questionnaires were sent to women who were consulting with new episodes of 'increased vaginal bleeding' and two groups of controls: consulting controls with 'acute respiratory tract infection' (RTI) or 'other illness' as identified by weekly computerised searches, and community controls, selected from the practice age-sex register. RESULTS: Nine hundred and forty-three questionnaires were sent out to 108 cases and 835 controls with an 80% response rate. Of these, 60.9% of the cases, 47.0% of the consulting controls, and 39.7% of the community controls were subjects with probable psychological distress on the General Health Questionnaire (chi2 test, P = 0.002). Cases were more likely than community controls to have heavy periods (odds ratio [OR] = 2.86, 95% confidence interval [CI] = 1.53-5.35) and heavy periods interfering with life (OR = 3.69, 95% CI = 2.02-6.75). After controlling for heaviness of periods, cases were still more likely to have psychological distress (OR = 1.80, 95% CI = 1.00-3.24). The same relationships prevailed when comparing cases and consulting controls. CONCLUSION: Interference in life caused by heaviness of periods appears to be a powerful initiator of consultation with increased vaginal bleeding. Perceived heavy periods and psychological disturbance are weaker predictors. Women presenting to primary care with increased vaginal bleeding are more likey to have a psychological disturbance than women from the community or those consulting with another illness.