A subconjunctival hemorrhage (sub-kun-JUNK-tih-vul HEM-uh-ruj) occurs when a tiny blood vessel breaks just underneath the clear surface of your eye (conjunctiva). The conjunctiva can't absorb blood very quickly, so the blood gets trapped. You may not even realize you have a subconjunctival hemorrhage until you look in the mirror and notice the white part of your eye is bright red.
A subconjunctival hemorrhage often occurs without any obvious harm to your eye. Even a strong sneeze or cough can cause a blood vessel to break in the eye. You don't need to treat it. Your symptoms may worry you. But a subconjunctival hemorrhage is usually a harmless condition that disappears within two weeks or so.
The most obvious sign of a subconjunctival hemorrhage is a bright red patch on the white (sclera) of your eye.
Despite its bloody appearance, a subconjunctival hemorrhage should cause no change in your vision, no discharge from your eye and no pain. Your only discomfort may be a scratchy feeling on the surface of your eye.
The cause of a subconjunctival hemorrhage isn't always known. The following actions may cause a small blood vessel to rupture in your eye:
- Violent coughing
- Powerful sneezing
- Straining
- Vomiting
In some cases, a subconjunctival hemorrhage may result from an eye injury, including:
- Roughly rubbing your eye
- Trauma, such as a foreign object injuring your eye
Risk factors for a subconjunctival hemorrhage include:
- Diabetes
- High blood pressure (hypertension)
- Certain blood-thinning medications, such as warfarin (Coumadin, Jantoven) and aspirin
- Blood-clotting disorders
Health complications from a subconjunctival hemorrhage are rare. If your condition is due to trauma, your doctor may evaluate your eye to ensure you don't have other eye complications or injury.