Subconjunctival hemorrhage may be caused by trauma, infection, high blood pressure and other reasons. 1. Trauma: Subconjunctival hemorrhage can be caused if the eye is damaged by external stimuli, such as debris in the eye, drugs attacking the eye, and X-ray irradiation of the eye. 2. Infection: eye lesions are commonly associated with acute bacterial infections of the conjunctiva, viral infections of the conjunctiva, etc., which may result in obvious subconjunctival hemorrhage. 3. High blood pressure: If there is high blood pressure, the blood vessels in the conjunctiva area may rupture and bleed, leading to the appearance of the symptom of subconjunctival hemorrhage. If subconjunctival hemorrhage occurs, you should go to the ophthalmology hospital in time and follow the doctor’s instructions for treatment.