What is subconjunctival hemorrhage?

Subconjunctival hemorrhage is the term for a broken blood vessel on the surface of the eye. The clear membrane that lines the inside of the eyelid and covers the white of the eye is called the conjunctiva. It has many very small blood vessels that break easily. When a break happens, blood can leak under the conjunctiva. When this happens, the blood causes part of the white of your eye to turn bright red.

The red spots caused by subconjunctival hemorrhage can look scary. But most cases do not cause any symptoms or need treatment. It is most common in older people, but it can happen at any age.

What causes a subconjunctival hemorrhage?

Most cases of subconjunctival hemorrhage have no known cause. Some events and conditions can cause blood vessels on the eye to break. These include:

  • Straining (during coughing, sneezing, vomiting, or while using the toilet)
  • Injury to the head or eye, including infection
  • Rubbing the eye too hard
  • Wearing contact lenses
  • Taking medications, including blood thinners and a cancer drug called interferon

What are the symptoms of subconjunctival hemorrhage?

Other than the red spot, there are no symptoms associated with subconjunctival hemorrhage. It does not cause pain or swelling, and it does not affect your vision. Most people who have so-called “red eye” do not even know it until they look in a mirror or someone tells them.

Last reviewed by a Cleveland Clinic medical professional on 02/20/2018.


  • American Academy of Ophthalmology. What is a Subconjunctival Hemorrhage? Accessed 2/20/2018.
  • Tarlan B, Kiratli H. Subconjunctival hemorrhage: risk factors and potential indicators. Clin Ophthalmol. 2013;7:1163-70.
  • Leibowitz HM. The red eye. N Engl J Med. 2000;343(5):345-51.

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