Subconjunctival haemorrhage | What is it, Causes and Treatment

Subconjunctival haemorrhage

Subconjunctival haemorrhage – Written by Dr. Eamonn Fahy, MB, BCh, BAO, Ph.D.

What is subconjunctival haemorrhage?

A subconjunctival haemorrhage is bleeding which occurs under the conjunctiva of the eye. The conjunctiva is the outer skin of the eye, which is a thin layer of clear tissue and is located over the white part of the eye and lines the inside of the eyelids. It is a very common eye condition and occurs when blood vessels under the conjunctiva are broken. Usually, the condition is not serious and will resolve on its own. Rarely, it can be a sign of serious trauma.


subconjunctival haemorrhage
Figure 1. Anatomy of the eye

The following overview will cover the causes of subconjunctival haemorrhage, its common signs and symptoms, its progression, diagnosis, and treatment options, as well as how it can be prevented.

subconjunctival haemorrhage
Figure 2. Eye showing subconjunctival haemorrhage

Causes of subconjunctival haemorrhage

There are several reasons that may cause subconjunctival haemorrhage, which include:

  • Eye rubbing: Eye rubbing is one of the most common causes of subconjunctival haemorrhage and can be triggered by dry or irritated eyes.
  • Coughing or straining: Severe coughing or sneezing can cause subconjunctival haemorrhage, as can straining while on the toilet or vomiting.
  • Trauma causing injury: This can range from mild trauma due to a small foreign body, for example, a particle of grit irritating the eye, to serious trauma from high velocity injuries such as firearm injuries.
  • Blood thinning medications: Medications such as aspirin, clopidogrel, warfarin or apixaban can increase the risk of subconjunctival haemorrhage, either following mild injury or spontaneously.
  • High blood pressure: High blood pressure can increase the risk of subconjunctival haemorrhage, either following mild injury or spontaneously.
  • Blood clotting disorders: Health conditions in which there is difficulty in clotting blood can increase the risk of subconjunctival haemorrhage.
  • Recent surgery: It is common for subconjunctival haemorrhage to occur following eye surgery, for example cataract surgery.
  • Conjunctivitis: Eye infections causing conjunctivitis which is the inflammation of the conjunctiva can rarely also cause subconjunctival haemorrhage.

What are the common symptoms and signs of subconjunctivital haemorrhage?

An obvious sign of subconjunctival haemorrhage is waking up and noticing that the white of the eye is red. This is usually caused by unintentional eye rubbing while asleep.

Other symptoms of subconjunctivital haemorrhage include:

  • Red eye
  • Irritated eye
  • Feeling that something is in the eye
  • Eye swelling
  • Mildly blurred vision

If you experience any of these signs and symptoms, schedule an appointment with an eye health professional to get your eyes checked. It is also important to note that the development of eye conditions may even start before symptoms appear, which makes going for regular and timely eye checks that much more essential.

How can subconjunctival haemorrhage progress?

Subconjunctival haemorrhage will resolve on its own and does not tend to progress unless there are untreated medical conditions, such as high blood pressure, that can cause an increased risk of the condition. Those with conditions such as chronic cough or blood-clotting disorders can increase the risk of recurrent subconjunctival haemorrhage.

How is subconjunctival haemorrhage diagnosed?

subconjunctival haemorrhage
Figure 3. Patient getting eyes checked by an eye health professional with a slit lamp

Subconjunctival haemorrhage is diagnosed by an eye health professional based on a comprehensive eye check. Questions are asked regarding overall health and any recent injuries to work out the cause of the haemorrhage and an eye examination is performed using a slit lamp (a microscope used to look at the eye) to have a closer look at the structures at the front of the eye.

How is subconjunctival haemorrhage treated?

Usually, subconjunctival haemorrhage will resolve on its own over the course of 1 to 2 weeks. There is no treatment that can speed up its recovery but there is no danger in the eye being red during this time. If it does not resolve on its own after 1 to 2 weeks seek medical advice from an eye health professional or a medical doctor. The eye may be mildly irritated while the haemorrhage is present, and your eye health professional may prescribe lubricant eye drops to improve comfort.

Can subconjunctival haemorrhage be prevented?

Treating of conditions that increases the risk of subconjunctival haemorrhage can help to prevent it, for example, treating dry eyes, managing chronic cough and controlling high blood pressure.

The information, including but not limited to, text, graphics, images and other material contained on this website are for informational purposes only. No material on this site is intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition or treatment and before undertaking a new healthcare regimen, and never disregard professional medical advice or delay in seeking it because of something you have read on this website.

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