The conjunctiva is the thin layer that covers the inside of the eyelids and the surface of the eye. It contains many tiny blood vessels that bring oxygen and nutrients to the eye. The sclera is the white part of the eye that is under the conjunctiva. Sometimes a blood vessel in the conjunctiva breaks and bleeds. The blood then collects under the conjunctiva and turns part of the eye red. Over a few weeks, your eye then absorbs the blood.

A subconjunctival hemorrhage can look quite alarming, but it's common and often harmless. They can happen to people of any age. Older adults have them more often.

In many cases, the cause is not known. But some health conditions may increase the risk. These include:

• Eye injury (including eye surgery)
• High blood pressure
• Inflammation of the conjunctiva
• Contact lens use
• Diabetes
• Hardening of the arteries
• Tumor of the conjunctiva
• Diseases that impair blood clotting
• Violent sneezing, coughing, or vomiting
• Certain medicines that can increase bleeding, like aspirin
• Pushing hard during a baby's delivery
• Straining because of constipation

Some of these causes, such as eye injury and contact lens use, are more common in young adults. Others, such as high blood pressure and diabetes, are more common in older adults.

Other than a red eye, you likely won't have any symptoms. You might feel like you have something in your eye. But this is not common. The hemorrhage shouldn't affect your vision. And it shouldn't cause any pain. If you do have pain, you may have another problem with your eye.

Some people notice a red eye after an eye injury. Other people might notice their hemorrhage without any injury. They may notice it after waking up in the morning.

In most cases, just one eye will have a hemorrhage. It typically happens once and then goes away. But some health conditions might cause repeated hemorrhages.

Your doctor will ask about your health history. You may have a physical exam. This includes a basic eye exam. A primary care doctor will often make the diagnosis. They will rule out other causes of red eye that might need other treatment.

Your primary care doctor might send you to an eye doctor if they think you may have a different problem with your eye. You will need to see an ophthalmologist (a doctor who specializes in eye problems) if you have had a serious eye injury. Your doctor might use a special lighted microscope to look at your eye in more detail. This helps to show if the injury went deeper or just involved the conjunctiva.

If this is your first subconjunctival hemorrhage, your doctor may not give you more tests. If you have had more than one, your doctor may need to check for a cause. For example, you may need blood tests to see if you have a blood clotting disorder.

Most people will not need any treatment. This condition often goes away on its own. It will likely go away in a few weeks. It will first turn from red to brown, and then to yellow. Currently, there are no treatments that will speed up this process.

Your doctor will mainly focus on treating any underlying disorders that might have caused your subconjunctival hemorrhage. For example, you may need a blood pressure medicine if high blood pressure may have helped to cause it.

In most cases, a subconjunctival hemorrhage is not preventable. Seeking regular treatment for your other health conditions may help prevent some cases of a subconjunctival hemorrhage.

Contact your doctor if your subconjunctival hemorrhage does not go away in 2 to 3 weeks. Also call your doctor right away if you have pain in the eye or vision loss.

If you have a history of eye injury or repeated hemorrhages, get your eye evaluated. An eye doctor needs to examine your eye and rule out more dangerous causes. You may also need to see your general doctor to rule out other problems, such as high blood pressure or a bleeding disorder.

• A subconjunctival hemorrhage is when a blood vessel breaks on the surface of the eye. It causes a bright red patch in the white of the eye.
• It may look alarming. But it is generally harmless.
• In many cases, the cause is not known. But some health conditions may increase the risk.
• Your doctor may need to rule out other more serious causes of your red eye. You might need to see an ophthalmologist.
• Most people will not need any treatment. This condition often goes away on its own in a few weeks.

Tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your doctor tells you.
• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you.
• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your doctor if you have questions.