Causes of subconjunctival hemorrhage.

We examined prospectively 8,726 patients in outpatient eye clinics. A total of 225 (2.9%) patients had subconjunctival hemorrhage. No sexual or age predilection was found. The most common causes for the condition were minor local trauma, systemic hypertension, and acute conjunctivitis. Subconjunctival hemorrhages resulting from local trauma were frequent in the summer, and those associated with systemic hypertension were noted most often in older patients. Blood pressures should be examined in patients with subconjunctival hemorrhages, particularly in older patients.