Subconjunctival Hemorrhage: What Patients Need to Know

Subconjunctival hemorrhage is a bright red patch on the white of the eye caused by a tiny broken blood vessel under the clear surface of the eye. It often looks alarming, but in many cases it is painless, harmless, and clears gradually without affecting vision.

What a subconjunctival hemorrhage is

A subconjunctival hemorrhage happens when a tiny blood vessel breaks beneath the conjunctiva, the thin, clear tissue that covers the white part of the eye. The blood becomes trapped under this transparent layer, creating a sharply defined red or dark red patch. Because the blood is on the surface rather than inside the eye, the appearance can seem more serious than it usually is.

Many people first notice it in a mirror or when someone else points it out. In most cases, there is no significant pain and vision stays normal. This is one of the key clues that helps distinguish a subconjunctival hemorrhage from more urgent eye problems.

The area may look bright red at first and then change color as it heals, sometimes becoming orange, brown, or yellow before disappearing. That color change is part of the normal breakdown of blood. A single patch may spread slightly over the first day before it begins to clear.

Although a subconjunctival hemorrhage is often harmless, it is still useful to understand when it may signal another issue. If there are other eye symptoms or if it keeps happening, a doctor can look for contributing factors such as blood pressure changes, medications, or an underlying eye condition.

How it looks and feels

The most common sign is a well-defined red patch on the white of one eye. It may cover a small area or spread across much of the sclera, the white part of the eye. Despite its appearance, it usually does not cause blurred vision, major discomfort, or discharge.

Some people notice a mild scratchy feeling, slight fullness, or awareness of the eye, especially if the bleed is large. However, a subconjunctival hemorrhage generally does not cause true eye pain. There is also usually no swelling of the eyelids and no thick discharge, which helps separate it from infections or deeper inflammation.

Symptoms that are not typical deserve more attention. These include reduced vision, sensitivity to light, severe headache, nausea, double vision, or pain with eye movement. Redness that forms a ring around the colored part of the eye or redness accompanied by trauma should not be assumed to be a simple surface bleed.

If a person is unsure whether the redness is a subconjunctival hemorrhage or another eye problem, an eye examination can help clarify the cause. This is especially important for people who wear contact lenses, have a known bleeding disorder, or have recently had an eye procedure.

Why it happens: common causes and risk factors

In many cases, no exact cause is found. A delicate blood vessel may simply break on its own during normal daily life. This is why a subconjunctival hemorrhage can appear suddenly even when a person does not recall any injury.

Common triggers are activities that briefly increase pressure in the small vessels of the head and neck. These include coughing, sneezing, vomiting, heavy lifting, constipation with straining, or vigorous exercise. Eye rubbing, minor irritation, and small unnoticed bumps to the eye can also lead to a bleed.

Some health factors make a subconjunctival hemorrhage more likely. These include high blood pressure, diabetes, older age, use of blood-thinning medicines, and conditions that affect clotting. Dry, irritated eyes may also encourage rubbing, which can contribute to broken vessels. If dryness is a recurring problem, a clinician may also assess for other surface eye conditions such as conjunctival irritation and inflammation.

Less commonly, recurrent or unusually extensive bleeding may be linked to an underlying bleeding tendency, poorly controlled blood pressure, or trauma. A doctor may ask about medicines such as aspirin or anticoagulants, recent illness, and episodes of bruising or bleeding elsewhere in the body. This broader history helps determine whether the eye finding is truly isolated.

How doctors diagnose it

Diagnosis usually begins with a simple history and eye examination. A clinician looks at the pattern of redness, asks whether there was trauma, and checks for pain, discharge, light sensitivity, or any change in vision. In a typical subconjunctival hemorrhage, the diagnosis is often straightforward on visual inspection alone.

The main goal is not only to confirm the surface bleed but also to rule out more serious causes of a red eye. Depending on the situation, the doctor may examine the cornea, measure vision, check the pupils, and look for signs of deeper eye injury or inflammation. Patients with pain or blurry vision may need a more detailed assessment by an eye specialist, such as through ophthalmology evaluation.

If the hemorrhage happened after an injury, additional testing may be needed to look for scratches, internal bleeding, or damage to the structures of the eye. This is particularly important after sports injuries, falls, traffic accidents, or anything involving sharp objects. The outside redness alone does not show whether there is trauma deeper in the eye.

Most people do not need blood tests for a one-time, uncomplicated episode. However, recurrent episodes, extensive bleeding, or associated bruising may prompt blood pressure measurement or laboratory evaluation. When there are repeated surface eye problems or uncertainty about the diagnosis, doctors may also evaluate for other eye conditions or refer for a fuller eye exam.

Treatment and expected recovery

Most subconjunctival hemorrhages do not require specific treatment. The trapped blood gradually clears as the body reabsorbs it, usually over 1 to 2 weeks, though larger areas may take a little longer. During that time, the color may change just as a bruise on the skin changes color.

If the eye feels mildly irritated, preservative-free artificial tears can improve comfort. Resting the eyes, avoiding rubbing, and taking a break from anything that causes strain may also help. The blood itself cannot usually be “washed out” with eye drops, so treatment focuses on comfort rather than making the redness disappear faster.

If there is an identified trigger, addressing it can reduce recurrence. For example, managing constipation, controlling cough, reviewing blood pressure, or discussing blood-thinning medication use with a doctor may be appropriate. Any medication change should be guided by a qualified clinician, especially if a blood thinner was prescribed to prevent stroke or heart problems.

When the redness is part of a broader eye issue, treatment depends on the underlying cause. An eye specialist may recommend further testing or management if there is concern about trauma, persistent irritation, or another diagnosis. In selected cases, patients may benefit from a comprehensive eye examination and follow-up care to ensure the eye is healing as expected.

Self-care and ways to lower the chance of recurrence

Self-care is mainly supportive. It helps to avoid rubbing the eye, use lubricating drops if there is dryness, and follow contact lens hygiene carefully if lenses are worn. People who notice the redness after a coughing illness or a bout of vomiting may simply need time for the vessels to settle.

General health measures can also play an important role. Blood pressure monitoring, good diabetes management, and staying hydrated may support eye and blood vessel health overall. If constipation or heavy straining is common, discussing practical prevention strategies with a healthcare professional may reduce repeated episodes.

Protective eyewear is sensible during sports, home repairs, gardening, or workplace tasks that could cause eye injury. Surface bleeding after trauma may still be minor, but protection lowers the risk of more serious damage that can affect vision. People who have had recent eye surgery should follow all post-procedure instructions carefully and report unexpected redness.

For individuals with recurrent symptoms, keeping a simple note of timing, associated activities, and any other bleeding symptoms can be useful at the medical visit. This helps the doctor identify patterns and decide whether further evaluation is needed. If symptoms are persistent or complicated, assessment through medical check-up services may help look for contributing health factors.

When to seek medical care

A person should seek prompt medical care if a red eye is accompanied by pain, blurred vision, double vision, sensitivity to light, severe headache, nausea, or significant swelling. These features are not typical of a simple subconjunctival hemorrhage and can point to a more urgent eye condition. Care is also important if the redness follows a direct injury, especially if there was a high-speed object or chemical exposure.

Medical review is also sensible if the hemorrhage keeps returning, appears in both eyes, or happens along with easy bruising, nosebleeds, or bleeding gums. These patterns can suggest an underlying health or clotting issue that deserves evaluation. People taking anticoagulants should not stop them on their own, but they should let their doctor know about recurrent bleeding.

Anyone with recent eye surgery, contact lens-related pain, or a known eye disease should be cautious about assuming all redness is harmless. A clinician can confirm the diagnosis and decide whether treatment is needed. Near the end of the care pathway, some patients may benefit from specialist follow-up; Acibadem International’s multidisciplinary specialists and JCI-accredited hospitals diagnose and treat eye conditions for international patients.

In general, a painless red patch with normal vision often improves on its own. Still, uncertainty is a good reason to ask a qualified doctor or eye specialist, especially when symptoms do not fit the usual pattern. Early assessment can provide reassurance and help protect vision when a different problem is present.

Frequently asked questions

Is a subconjunctival hemorrhage dangerous?

Usually, no. In many cases it is a harmless surface bleed that clears on its own and does not affect vision. It should be assessed promptly if it comes with pain, vision changes, or follows an injury.

How long does a subconjunctival hemorrhage last?

Most clear within 1 to 2 weeks, though larger ones may last a little longer. The red patch often changes color as it heals, similar to a bruise. This gradual fading is normal.

Can high blood pressure cause a subconjunctival hemorrhage?

High blood pressure can be a contributing factor, especially in recurrent cases, although it is not the cause every time. A doctor may recommend checking blood pressure if the bleeding happens more than once or if there are other risk factors.

Should contact lenses be worn during a subconjunctival hemorrhage?

It is often wise to avoid contact lenses until the eye feels comfortable and a clinician confirms there is no other problem. If there is pain, discharge, or light sensitivity, contact lenses should be removed and medical advice sought promptly.

Can eye drops make the blood go away faster?

Lubricating eye drops can ease irritation, but they do not usually speed up the absorption of the blood. The redness fades as the body naturally clears it. Any medicated drops should only be used if recommended by a doctor.

Why did it happen if there was no injury?

A subconjunctival hemorrhage often happens without a clear injury. Coughing, sneezing, straining, rubbing the eye, or even normal daily activity can be enough to break a tiny vessel. Sometimes no trigger is found at all.

References

• American Academy of Ophthalmology
• National Eye Institute
• Mayo Clinic
• Merck Manual Consumer Version

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.