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). In many ways, it's just like having a bruise on your skin. 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 that 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. A subconjunctival hemorrhage may look alarming, but it's 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 looks worse than it is and should cause no change in your vision, discharge or pain. Your only discomfort may be a scratchy feeling on the surface of the eye.

When to see a doctor

If you have recurrent subconjunctival hemorrhages or other bleeding, talk to your doctor.

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.

If the bleeding on the surface of your eye has a clearly identifiable cause, such as a bleeding disorder or blood-thinning medication, ask your doctor if you can take any steps to reduce the risk of a subconjunctival hemorrhage.

If you need to rub your eyes, rub them gently. Rubbing too hard can cause minor trauma to your eyes, which may lead to a subconjunctival hemorrhage.

Your doctor or eye doctor will generally diagnose a subconjunctival hemorrhage by looking at your eye. You'll likely need no other tests.

If you have recurrent subconjunctival hemorrhages, your doctor may also:

• Ask you questions about your general health and symptoms
• Conduct an eye examination
• Take your blood pressure
• Obtain a routine blood test to make sure you don't have a potentially serious bleeding disorder

You may want to use eye drops, such as artificial tears, to soothe any scratchy feeling you may be experiencing. Beyond that, the blood will absorb within about 1 to 2 weeks, and you'll need no treatment.

You're likely to start by seeing your primary care doctor. In some cases when you call to set up an appointment, you may be referred immediately to an eye doctor (ophthalmologist).

Here's some information to help you get ready for your appointment.

What you can do

• List any symptoms you're experiencing, including any that seem unrelated to the reason for which you scheduled the appointment.
• List key personal information, including any major stresses or recent life changes.
• List all medications, vitamins and supplements that you're taking, including doses.
• List questions to ask your doctor.

Preparing a list of questions may help you make the most of your time with your doctor. For a subconjunctival hemorrhage, some basic questions to ask your doctor include:

• What might have caused this problem?
• Will it happen again?
• Do I need any tests?
• Are there any treatments for this condition?
• Are there any restrictions that I need to follow?
• Do I need to be referred to a specialist?
• Do you have any brochures or other printed material that I can take home with me? Do you recommend that I visit a website related to this problem?

Don't hesitate to also ask questions that occur to you during your appointment.

What to expect from your doctor

Your doctor is likely to ask you a number of questions, such as:

• When did you first notice the problem?
• Do you have any symptoms associated with this?