Blood in the Eye: How Alarmed Should You Be When Your Eye White Is Scary Red? – Everyday Health
June 15, 2022
On an otherwise uneventful morning, you look in the mirror and … there’s blood in your eye!
Odds are you have a subconjunctival hemorrhage, or burst blood vessel. Predominantly caused by a minor injury or strain, a subconjunctival hemorrhage that isn’t recurrent or persistent is almost always harmless, even if it doesn’t look that way.
“A subconjunctival hemorrhage can be confusing, scary, and pretty impressive looking if you’ve never seen it before, but it’s rarely anything to worry about,” says Emily Witsberger, MD, an adult and pediatric cornea specialist at the Mayo Clinic in Rochester, Minnesota.
What Is Subconjunctival Hemorrhage?
Sometimes called a blood spot, a subconjunctival hemorrhage is actually a bruise to the eye that often seems to appear out of nowhere. In reality, it likely followed an unremarkable or unrecognized injury (rubbing your eyes long and hard, for example). Blood-thinning medication and some medical conditions can also cause a small blood vessel in the eye to spring a leak.
Fragile vessels nourish the conjunctiva, the transparent tissue lining the insides of the eyelids and covering the sclera — the eyeball’s white outer layer. Occasionally these vessels rupture, sending a small amount of blood into the microscopic space between the conjunctiva and the sclera. The resulting spot appears flat, uneven, and vividly red.
“A pool of blood has collected right underneath the clear layer of the eye, and it shows up as completely red, like the surface of a tomato,” says Dr. Witsberger.
Like a bruise, the mark normally fades over days or weeks, changing from red to purple to green and then yellow.
People over age 50 and the elderly, especially older individuals with diabetes, hypertension (high blood pressure), hyperlipidemia (an abnormally high blood concentration of fats and lipids), or other underlying vascular conditions, are more prone to spontaneously develop these kinds of blood spots. But younger people, especially those who engage in vigorous sports and activities, can easily burst an ocular blood vessel.
Women have been known to develop blood spots during childbirth. Some babies, too, can enter the world with a vessel that probably burst from changes in pressure on the newborn’s body during childbirth.
What Causes a Burst Blood Vessel in the Eye?
Almost half of spontaneous cases of subconjunctival hemorrhage are idiopathic, meaning there is no known — or no remembered — cause. The ordinary stress or strains of daily life, fleeting moments of extreme exertion, an insignificant bump, or a barely perceived illness can quietly lead to a leak.
Some systemic conditions tend to weaken blood vessels, making them more susceptible to the rigors of daily life. Those ailments include bleeding or blood clotting disorders, high blood pressure, diabetes, elevated cholesterol, and other cardiovascular issues.
But, as Witsberger points out, “there are several different ways in which blood vessels can become broken.” Among the most common:
Straining Pushing your body to its limits, whether during an intense workout or while pulling, pushing, or lifting heavy objects can exert enough internal pressure for blood vessels to spout a little blood.
“People who engage in weightlifting, or those who have a condition that makes them more likely to be constipated, are the kinds of patients we see frequently,” says Witsberger. Straining to have a bowel movement, energetic coughing, sneezing, vomiting, laughing, crying — all generate the kind of internal pressure that could prompt a blood bleed in the eye.
Teeth Clenching and Breath Holding Both of these internal bodily actions can precipitate a subconjunctival hemorrhage. Breath holding includes the Valsalva maneuver, a breathing technique that nudges a runaway heartbeat into a normal rhythm.
Injury Sports lead the pack when it comes to eye-threatening injuries. The American Academy of Family Physicians ranks basketball, water sports, baseball, and racquet sports as those posing the most potential harm to eyes.
Certain extreme leisure pursuits or sports also pose a risk to the eyes. Bungee jumping, ziplining, and riding your favorite killer roller coaster are the kinds of activities that create the sudden air pressure changes, extreme muscle tension, and quick, forceful movements that can blow an eye blood vessel.
Contact Lenses Improper lens insertion or removal can damage the surface of the eye, while material defects in the lenses themselves can similarly create harm. The prolonged use of disposable lenses can introduce infection, provoking discomfort and the eye rubbing that can precipitate subconjunctival hemorrhage. (Most doctors suggest that people wear glasses while waiting for a subconjunctival hemorrhage to heal so that no additional irritation from contact lenses takes place.)
Systemic Conditions High blood pressure powerfully affects eyes but rarely triggers a bleed in someone without the presence of other conditions. That said, hypertension is still cited as a proven risk for subconjunctival hemorrhage, even when blood pressure is apparently well controlled by medication. Indeed, some doctors consider frequent or recurrent subconjunctival hemorrhage to be a potential early warning sign of looming hypertension.
Diabetes and hyperlipidemia can weaken blood vessels over time, increasing the likelihood of a spontaneous rupture. Von Willebrand disease and hemophilia, the most common hereditary bleeding disorders, dramatically hike the risk of blood spots.
“Anyone who is an easy bleeder is at greater risk for subconjunctival hemorrhage,” says Witsberger.
Several studies, including one published in the July 2020 issue of Der Ophthalmologe, have reported that some people hospitalized in intensive care with COVID-19 faced greater odds of developing subconjunctival hemorrhage. (Whether the subconjunctival hemorrhage resulted from the use of anticoagulants, severe coughing, vomiting in reaction to medication, or some other cause wasn’t determined.)
Medication Any drug that inhibits blood clotting can promote a blood spot. The most popular anticoagulant, or “blood thinning,” medications are heparin and warfarin, with the latter a known contributor to subconjunctival hemorrhage. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen, which block chemicals that cause pain and inflammation, and drugs known as P2Y12 inhibitors (including clopidogrel), which prevent blood platelets from becoming too sticky, tend to increase subconjunctival hemorrhage risk.
Eye Surgery Any eye surgery can heighten the chance for developing subconjunctival hemorrhage, especially among people who are already taking anticoagulants. Cataract surgery, refractive (vision-improving) procedures, and local eye anesthesia can lead to a blood spot.
“When there’s been any trauma to the eye, including through surgical manipulation, it can lead to subconjunctival hemorrhage,” says Witsberger.
Unknowns Often the cause of an eye bleed is never pinpointed, leaving many people wondering whether an errant poke or prod occurred during sleep. That may explain why so many subconjunctival hemorrhages seem to materialize upon awakening.
How Is Subconjunctival Hemorrhage Diagnosed and Treated?
Through a careful exam, an eye doctor can determine if the redness is caused by blood trapped under the conjunctiva or by dilation of blood vessels, which can result from other conditions.
Treatment of subconjunctival hemorrhage can be as straightforward as the diagnosis. It may simply take time. Over a brief period, anywhere from a few days to about two weeks, the blood is usually resorbed into the body with no lasting effects.
While it fades, some people find cold compresses and artificial tears soothing. With or without treatment, however, the typical subconjunctival hemorrhage will quietly and completely vanish.
What Over-the-Counter ‘Treatments’ Should You Avoid?
Doctors advise scrupulously avoiding over-the-counter “get the red out” drops sold for bloodshot eyes.
“We routinely recommend against using those drops for any purpose,” Witsberger says. “They constrict blood vessels in the eye, and when you stop taking them, there can be a profound rebound effect, where the eyes become very red.” And the drops have no effect on the course of a blood spot.
Anyone with a history of eye bleeds should tread carefully when choosing painkiller, since aspirin, aspirin-related products, and NSAIDs, such as ibuprofen, could raise the risk of bleeding. They should also discuss with their doctor taking supplements such as fish oil, ginger, and turmeric, which are believed to have blood-thinning properties.
Doctors recommend that anyone who engages in a fast, high-energy sport or leisure activity — or in a hobby such as woodcutting, car repair, or soldering — seriously consider donning safety goggles.
The Bottom Line
A first-time subconjunctival hemorrhage generally merits a call or visit to the doctor. Recurrent incidents or a bloody eye accompanied by unfamiliar symptoms? Definitely call an eye doctor.
After that, the blood spot story is usually one of reassurance, patience, and good outcomes. Subconjunctival hemorrhage may be a sight to behold, but it’s mostly a harmless, brief, and self-limiting one.