Bloodshot Eyes: Causes and Treatment

By Craig Sorkin, DNP, APN
Medically reviewed checkmarkMedically reviewed
May 25, 2022

Red eye, also referred to as bloodshot eye, is a common problem that can affect one or both eyes.

While red eyes are not always the symptoms of an illness, they can sometimes be the sign of a serious vision problem.

Those with bloodshot eyes should be evaluated for other symptoms, such as visual abnormalities, abnormalities in eye appearance, and eye sensory abnormalities (pain).

This article explores the causes, symptoms, and treatments of bloodshot eyes.

What Causes Red, Bloodshot Eyes?

Bloodshot eyes can indicate the presence of several different health issues.

While some of these issues are benign, others can be serious and require emergency medical attention.

Bloodshot eyes occur when small blood vessels on the surface of the eye become enlarged and congested with blood. On their own, red eyes are not usually a reason for concern.

But red eyes along with pain, watering, dryness, or impaired vision, can indicate a serious medical problem.

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Common Causes of Red Eyes

Below, we’ll explore the different causes of eye redness in detail.

Dry eye syndrome 

If your body does not produce an adequate amount of tears to lubricate and nourish your eyes, you may develop dry eye syndrome.

Hormonal changes, some medical conditions, and some medications can cause dry eye syndrome.

Chronic dry eye can cause the surface of the eye to become red, inflamed, and irritated.

Symptoms of dry eye syndrome include:

  • Stinging or burning eyes
  • A feeling that something is in the eye
  • Pain and redness in the eye
  • Excessive tears
  • Discomfort when wearing contact lenses
  • Blurry vision
  • Eye fatigue
  • Stringy eye discharge
  • Discomfort after watching television or reading

Allergies

Allergies can affect the eyes, causing them to become red and swollen.

Other symptoms that you may experience include:

  • Itching
  • A burning sensation
  • Increased tearing

Eye allergy symptoms can also be accompanied by other allergy symptoms, such as sneezing and an itchy, runny nose.

Some common allergy triggers include:

  • Pollen
  • Dust mites
  • Mold
  • Pet dander
  • Irritants like cigarette smoke or air pollution

Conjunctivitis

Conjunctivitis, or pink eye, is an infection of the conjunctiva—a thin transparent membrane that lines the inside of the eyelid and loops back to cover the white part of the eye.

The infection causes the blood vessels in your conjunctive to swell, giving the whites of your eye a pinkish or reddish color.

Additional signs and symptoms of conjunctivitis include:

  • Itchy eye
  • Excess tear production
  • Redness
  • Discharge
  • Sensitivity to light
  • Poor vision
  • A gritty feeling in one or both eyes

Viruses cause as many as 80% of all conjunctivitis cases.

Some other causes include bacteria, fungi, exposure to chemicals or allergens, a foreign body in the eye, and the use of contact lenses.

Pink eye often affects both eyes because the infection typically spreads from one eye to the other.

Uveitis 

Uveitis is inflammation that happens in the middle part of your eye, called the uvea. The uvea is an area found between the white of your eye and your retina.

Inflammation due to uveitis can lead to eye redness.

Additional symptoms to look out for are:

  • Blurred vision
  • Eye pain
  • Eye floaters
  • Sensitivity to light

Dry eyes

Tears are made by small glands above your eyes.

They work to help protect and lubricate the eyes. When your eyes don’t produce enough tears, you have dry eyes.

Dry eyes are very common, with studies estimating a prevalence of 5%-50%.

The condition is more likely to occur in women, people over the age of 50, and individuals who wear contact lenses.

If you have dry eyes, you may notice that your eyes appear red.

Other symptoms include:

  • A stinging, scratchy, or burning sensation
  • Feeling like something is in your eye
  • Sensitivity to light
  • Blurred vision

Angle-closure glaucoma

Glaucoma is a condition where the pressure in your eye increases because your eye is producing more fluid than the normal amount.

This can damage your optic nerve, potentially leading to vision loss. 

Angle-closure, or narrow-angle, glaucoma is a less-common form of glaucoma that causes a rapid increase in eye pressure.

The symptoms of angle-closure glaucoma come on suddenly and may include eye redness as well as other, additional symptoms:

If left untreated, angle-closure glaucoma may cause rapid vision loss.

Blepharitis

Blepharitis is an inflammation of your eyelids that can cause your eyelids or eyes to appear red and swollen.

Some additional symptoms of blepharitis are:

  • Itching
  • A burning or stinging sensation
  • Feeling like something is in your eye
  • Increased tearing
  • Crusty eyelids in the morning
  • Sensitivity to light

Injury 

Sustaining an injury that affects your eye may cause it to redden, often due to irritation or bleeding.

Other symptoms that may occur with an eye injury include:

  • Eye pain
  • Swelling of the eye or the surrounding area
  • Trouble moving your eye
  • Decreased vision
  • Different pupil sizes

A few examples of common sources of eye injuries include:

  • Foreign objects that get into your eye
  • Physical trauma, such as sustaining a blow or an accident
  • Exposure to chemicals

Subconjunctival hemorrhage 

The conjunctiva contains many blood vessels and capillaries.

When these vessels break, blood flows into the area between the conjunctiva and the white of the eye, which leads to a small amount of blood building up under the conjunctiva.

This accumulation is called a subconjunctival hemorrhage.

The minor bleeding under the eye’s outer membrane causes bright red spots to appear on the white of the eye. 

A subconjunctival hemorrhage can result from a minor injury or trauma to the eye, including rubbing the eye due to allergies, as well as coughing, sneezing, and straining. 

People who have diabetes, have high blood pressure, or take certain medications, such as blood thinners, may have a higher risk of a subconjunctival hemorrhage.

Eyelid stye

A stye is a blockage of the meibomian gland in the eye that causes inflammation. It can affect the outside or inside of either your upper or lower eyelid.

If you have a stye, the area at the edge of your eyelid can become red, swollen, and painful.

The affected area may fill with meibum (due to the blocked gland) and can potentially grow to the size of a pea.

Corneal ulcers

A corneal ulcer is an open sore on the cornea that can result from a bacterial, viral, fungal, or parasitic infection. Symptoms can include:

  • Red eyes
  • Pain or soreness
  • Sensitivity to light
  • Mild-to-severe eye discharge
  • Reduced vision
  • A white spot on the cornea

Scratches, burns, dry eye syndrome, and conditions that affect eyelid function can also increase the risk for a corneal ulcer.

Scleritis

Scleritis is an inflammation of the white of your eye, which is called the sclera.

When this occurs, the white of your eye can become red and swollen, in addition to:

  • Increased tearing
  • Eye tenderness or pain
  • Blurred vision
  • Sensitivity to light
  • Pain in the head, face, or jaw
  • Decreased vision

Additional causes

Various medical conditions can cause red eyes, such as:

  • Cellulitis
  • Eye lymphoma
  • Herpes zoster (shingles)
  • Toxoplasmosis

How to Treat Red Eyes

While red eyes often get better without treatment, eye drops may help ease any discomfort.

However, you should seek medical help if you are experiencing red eye along with any of the following symptoms:

  • An eye injury
  • Persistent symptoms
  • Pain
  • Vision loss

Common treatments include eye drops, antibiotics, creams, and oral medications.

Most cases of red eye are easily treatable and, if caught early, do not cause any permanent or long-term damage.

If red eye results from an underlying condition, you must visit a healthcare professional immediately for the right care.

Other Considerations

If you have milder symptoms, there are at-home treatments that can help ease discomfort:

  • Applying a cool compress a few times each day
  • Using artificial tears or lubricating ointments
  • Resting your eyes frequently
  • Avoiding activities that worsen symptoms
  • Wearing sunglasses to reduce light sensitivity
  • Washing your hands before touching your eyes

If symptoms do not improve or if they worsen, you should see a healthcare professional, because you may need medication.

Do not attempt to treat red eyes with over-the-counter (OTC) medications without talking to a healthcare professional first.

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When to Seek Medical Attention

Red eyes can be a symptom of several different conditions ranging from mild to serious concern. Treatment will vary depending on the underlying cause.

In most cases, red eyes can be treated at home with self-care measures.

However, if symptoms are severe or do not improve with home treatment, it is important to see a healthcare professional for further evaluation and treatment.

Depending on your diagnosis, the healthcare professional may prescribe a treatment that helps to alleviate your symptoms.

This will likely include some of the following:

  • Steroid eye drops or tablets
  • Antimicrobial medications, which may include eye drops, tablets, or a topical medication that you apply near your eye
  • Prescription eye drops for specific conditions like allergies, dry eye, or glaucoma
  • A laser procedure (in the case of acute angle-closure)

How K Health Can Help

Did you know you can get affordable primary care with the K Health app?

Download K Health to check your symptoms, explore conditions and treatments, and, if needed, text with a doctor in minutes. K Health’s AI-powered app is HIPAA compliant and based on 20 years of clinical data.

Frequently Asked Questions

What does a bloodshot eye indicate?
A bloodshot eye is usually a sign of conjunctivitis, also known as pink eye. This is a condition that causes the blood vessels in your eyes to become inflamed. Conjunctivitis can be caused by allergies, bacteria, viruses, or irritants in the air.
What can cause your eyes to go bloodshot?
There are many potential causes of bloodshot eyes, including conjunctivitis, scleritis, eye injuries, and underlying medical conditions.
Can bloodshot eyes be serious?
While bloodshot eyes are usually not serious, they can be a symptom of a more serious condition. If you experience persistent symptoms or pain, you should see a healthcare professional for further evaluation.
When should I be concerned about a bloodshot eye?
If you have a bloodshot eye and are also experiencing pain, vision loss, or symptoms that do not improve with home treatment, you should see a healthcare professional for further evaluation.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Craig Sorkin, DNP, APN

Craig Sorkin, DNP, APN is a board certified Family Nurse Practitioner with over 15 years experience. He received his Undergraduate and Graduate degrees from William Paterson University and his doctoral degree from Drexel University. He has spent his career working in the Emergency Room and Primary Care. The last 6 years of his career have been dedicated to the field of digital medicine. He has created departments geared towards this specialized practice as well as written blogs and a book about the topic.