Bloodshot Eyes May Be a Sign of This Serious Condition


If you just caught sight of yourself in the mirror and noticed that your eyes are bloodshot, there are a few possible reasons why. Allergies can cause red, itchy eyes (although you need to figure out exactly what you're allergic to!). Conjunctivitis—also known, appropriately, as pinkeye—is a common, and highly contagious, illness. A sleepless night, tobacco use, or leaving your contact lenses in too long can also cause red eyes. Unfortunately, bloodshot eyes can also indicate a more serious condition. Read on to find out when you should see a doctor about your irritated eyes.

RELATED: If You Notice This Around Your Eyes, Get Your Liver Checked.

What causes bloodshot eyes?

We've all had bloodshot eyes at one time or another, but you might not know what causes the condition. When tiny blood vessels under the surface of the eye become congested, larger, and inflamed, this results in reddened eyes, as the Cleveland Clinic explains. (A broken blood vessel, however—called a subconjunctival hemorrhage—can result in trapped blood that looks more dramatic and appears like a red blotch on the white part of the eye, says the Mayo Clinic.)

Blood vessels become enlarged and irritated for many different reasons. Inflammation can be caused by allergies or illness; crying also causes vessels to dilate, thus increasing flood flow to the eyes, and dryness—from being on an airplane or sitting in front of the computer—can also create redness. Some of these issues will resolve on their own, but other times, bloodshot eyes can indicate a severe condition that requires medical attention, such as glaucoma, uveitis, or infection.

Bloodshot eyes can be a warning sign of glaucoma.
FG Trade/iStock

According to the National Eye Institute, glaucoma is "a group of eye conditions that damage the optic nerve, the health of which is vital for good vision." Caused by increased eye pressure, glaucoma can result in permanent vision loss. Glaucoma is a serious illness; it's the second leading cause of blindness in the world, and about 15 percent of people suffering from it become blind in at least one eye—even with treatment.

The symptoms of glaucoma can be mild and gradual, and often people don't realize that they have the condition. Bloodshot eyes can be a warning sign—and an opportunity to treat the problem, as the damage caused by glaucoma is irreversible. There are different risk factors for glaucoma. The National Eye Institute people with diabetes, Latinos over 60, African Americans over 40, and those with a family history of glaucoma are at increased risk.

Uveitis is another a form of eye inflammation.

A type of eye inflammation called uveitis could also be behind your bloodshot eyes. The Mayo Clinic explains that the exact cause of uveitis is not always known, but possible reasons behind the condition can include an infection, and autoimmune or inflammatory disorder, an eye injury, side effects of medication, and, rarely, cancer. If untreated, uveitis can worsen and lead to permanent vision loss, as well as other problems such as retina scarring, cataracts, and nerve damage. In addition to bloodshot eyes, the National Eye Institute lists the following symptoms that can indicate uveitis: blurry vision, light sensitivity, pain in the eye area, and spots or lines in your vision known as "floaters."

While uveitis often affects people between the ages of 20 and 60, anyone can be afflicted. Since reddened eyes can indicate a benign form of inflammation such as dry eyes or pinkeye, it can go undetected as a potential symptom of uveitis.

RELATED: For more up-to-date information, sign up for our daily newsletter.

Bloodshot eyes can indicate an infection.

Another potential serious reason for bloodshot eyes can be an infection that resides in the eye or has spread from another part of the body, causing the inflammation of blood vessels. Some infections need medical attention, as they can worsen and lead to serious vision problems and even loss of the eye. Web MD says additional symptoms of infections such as keratitis, blepharitis, and endophthalmitis can include pain and swelling in the eye area, decreased ability to see, and discharge. There are many different causes for eye infections, which range from injury to the eye (such as an accident or a problem during eye surgery) to bacterial, fungal, or viral illness.

Although there are so many potential reasons for bloodshot eyes, there is a common factor: Having an examination by a medical professional who can provide relief—whether it is oral medication, eye drops, or even a surgical procedure—is crucial if you're experiencing them on a regular basis.

RELATED: If You Notice This With Your Eyes, Get Your Thyroid Checked, Doctors Say.