Subconjunctival hemorrhage

A subconjunctival hemorrhage is bleeding beneath the conjunctiva. The conjunctiva is the thin, clear membrane covering the white part of your eye and the inside of your eyelids.

Tiny blood vessels run through this membrane. If one breaks, blood can become trapped between the conjunctiva and the white of the eye. This creates a sharply defined red or dark patch.

The appearance can be dramatic, but an uncomplicated subconjunctival hemorrhage is usually harmless. It does not normally affect vision or cause lasting eye damage. Your body gradually absorbs the blood, much as it absorbs a bruise under the skin.

This condition is different from bleeding inside the eye. Blood that appears in front of the coloured iris or pupil, especially after an injury, needs urgent assessment.

The main sign is a bright red patch on the white of one eye. The patch may be small or may cover much of the visible white area.

A typical subconjunctival hemorrhage:

• Does not cause significant pain
• Does not blur or reduce vision
• Does not produce pus or sticky discharge
• Does not usually cause strong sensitivity to light

You may notice mild scratchiness, fullness, or irritation. Some people have no sensation at all and first notice the patch in a mirror or when another person points it out.

The patch can appear larger during the first day as blood spreads beneath the conjunctiva. As it heals, it may change from bright red to darker red, brown, yellow, or greenish tones. This colour change is similar to what happens as a skin bruise fades.

The blood is trapped under the clear membrane, so it should not wipe away. Tears may water slightly because of irritation, but they are not usually bloody.

Pain, reduced vision, marked light sensitivity, or thick discharge are not typical. These symptoms may point to another eye problem.

A subconjunctival hemorrhage happens when a small surface blood vessel breaks. In many cases, there is no clear trigger.

A sudden rise in pressure within the veins can sometimes break a fragile vessel. This may happen with:

• Forceful coughing or sneezing
• Vomiting
• Straining during a bowel movement
• Heavy lifting or other intense effort

Rubbing the eye, inserting a contact lens, or a minor poke can also injure a vessel. Subconjunctival bleeding may occur after eye surgery, an injection into the eye, or another eye procedure.

The chance may be higher in people with high blood pressure. Blood-thinning medicines, including anticoagulants and antiplatelet medicines, can make bleeding more likely or allow a larger patch to form. These medicines include treatments prescribed to prevent stroke, heart attack, or blood clots.

Less commonly, repeated or unusually extensive bleeding can be linked to a problem with platelets or blood clotting. Platelets are blood cells that help stop bleeding. Easy bruising, frequent nosebleeds, bleeding gums, or bleeding in both eyes may be important clues.

Blood vessels also become more fragile with age. However, a subconjunctival hemorrhage can happen at any age.

A healthcare professional can usually identify a subconjunctival hemorrhage by examining the eye and checking your vision. A slit lamp may be used. This is a microscope with a bright light that provides a magnified view of the eye.

The examination helps confirm that the blood is beneath the conjunctiva rather than inside the eye. It also looks for a scratch, foreign object, infection, or injury that may need different care.

A single painless episode with normal vision usually does not require laboratory testing. Your blood pressure may be checked, particularly if you do not know your usual reading or the bleeding has happened more than once.

If episodes keep returning, affect both eyes, or occur with bleeding elsewhere, further assessment may include a review of your medicines and blood tests. These tests can measure blood cell numbers and how well the blood clots.

After an eye injury, more detailed examination or imaging may be needed to rule out damage below the surface.

Most uncomplicated subconjunctival hemorrhages do not need treatment. The blood cannot be rinsed or wiped away, and there is usually no safe way to make it disappear immediately. Your body will absorb it over time.

Lubricating eye drops, sometimes called artificial tears, may ease mild scratchiness. They do not remove the blood or shorten healing time.

Avoid rubbing the affected eye. If contact lenses feel uncomfortable, leave them out until the eye feels normal. A contact lens wearer who has pain, strong light sensitivity, or discharge should obtain prompt medical advice because these symptoms can indicate a corneal infection rather than simple surface bleeding.

“Redness relief” drops that narrow surface blood vessels will not clear trapped blood. They may also cause more redness when used repeatedly.

Do not stop or reduce a prescribed blood thinner like warfarin or apixaban because of an eye patch without speaking with the professional who manages that medicine. Preventing a stroke, heart attack, or dangerous clot may be much more important than the appearance of the eye.

If the hemorrhage followed surgery or another eye procedure, follow the specific aftercare instructions provided by your eye team.

A simple subconjunctival hemorrhage rarely causes complications. The blood stays outside the structures responsible for sight, so it does not normally damage the cornea, retina, or optic nerve.

The patch may take longer to clear if it is large or if you use medicine that affects clotting. It can also return, especially if an underlying trigger remains.

Repeated episodes are not usually dangerous by themselves, but they can sometimes reveal uncontrolled high blood pressure, a medication-related bleeding tendency, or a blood-clotting problem. These possibilities are assessed based on your wider symptoms and medical history.

A red patch after significant trauma may occur alongside a deeper injury. In that situation, the concern is the injury rather than the surface hemorrhage itself.

Many subconjunctival hemorrhages cannot be prevented because they happen without a clear cause.

You may be able to reduce some triggers by avoiding forceful eye rubbing and wearing suitable eye protection during work, sport, or activities that could cause an eye injury. Careful contact lens handling may help prevent surface injury.

If coughing, vomiting, or constipation repeatedly triggers bleeding, managing that underlying problem may reduce future episodes. Regular blood pressure checks and treatment of known high blood pressure are also important for general health.

Take prescribed blood-thinning medicines exactly as directed. Do not change them to prevent eye redness unless the prescribing professional recommends a change after reviewing the risks and benefits.

Most patches begin fading within several days and disappear within about two weeks. A large hemorrhage may take two to three weeks, and occasionally longer, to clear fully.

The colour often changes during healing. It may also seem to move or spread as the blood settles beneath the conjunctiva. These changes do not necessarily mean that fresh bleeding is occurring.

Normal vision should remain unchanged. Most people can continue everyday activities, including reading, using screens, and working. If the episode followed an operation or injury, activity advice may be different.

Once the blood has cleared, the eye usually looks and feels normal. A previous episode does not usually cause permanent weakness or vision loss. Some people have another episode months or years later, while others never have one again.

Arrange routine follow-up if the patch is not clearly fading after two to three weeks, if episodes keep returning, or if you are concerned about your blood pressure or medicines. Recurrent bleeding may need a broader medical review even when each episode is painless.

Seek emergency care for a red or bloody-looking eye if you also have:

• Sudden loss or major change of vision
• Severe eye pain
• A significant eye or head injury
• A chemical splash or penetrating injury
• Blood visible in front of the iris or pupil
• New weakness, facial drooping, difficulty speaking, or a sudden severe headache

These features are not typical of a simple subconjunctival hemorrhage.

Obtain prompt, same-day advice if the redness comes with marked light sensitivity, increasing swelling, thick discharge, or moderate pain. Contact lens wearers should be especially cautious about these symptoms because infections can worsen quickly.

Arrange a routine appointment if the blood has not begun to clear within two to three weeks, keeps returning, or affects both eyes. You should also mention unexplained bruises, frequent nosebleeds, bleeding gums, or unusually heavy bleeding elsewhere.

If you take a blood thinner, report repeated or extensive episodes to the professional managing that medicine. Continue taking it unless you are specifically told otherwise.

How long does a subconjunctival hemorrhage last?

Most clear within about two weeks. A larger patch can take two to three weeks or occasionally longer. It should gradually fade or change colour during that time.

Is a subconjunctival hemorrhage contagious?

No. It is bleeding from one of your own small blood vessels, not an infection. You cannot pass it to another person.

Can stress cause a blood vessel to burst in my eye?

Emotional stress alone is not a well-established direct cause. However, stress may occur alongside temporary blood pressure changes, poor sleep, coughing, vomiting, or straining. Often, no specific cause can be identified.

Can I exercise with a subconjunctival hemorrhage?

Ordinary activity is usually possible if you have no pain, injury, or vision change. If heavy straining appears to have triggered the bleeding, it may be sensible to avoid repeating that activity while the eye settles. Follow different advice if the bleeding occurred after eye surgery or trauma.

Does it mean my blood pressure is too high?

Not necessarily. Subconjunctival hemorrhages also happen in people with normal blood pressure. Because high blood pressure can increase the likelihood of bleeding, checking it is reasonable if the episode is unexplained or keeps returning.

Why does it look serious if it does not hurt?

The conjunctiva is clear, so even a small amount of blood is easy to see against the white eye. The blood remains near the surface and usually does not involve the sensitive or vision-forming structures deeper in the eye.