---
title: What causes subconjunctival bleeding?
description: "[Subconjunctival bleeding](https://bluefinvision.com/blog/why-a-sudden-blood-red-eye-looks-frightening-but-is-usually-harmless/) occurs when a small blood vessel breaks under the conjunctiva, creating a sharply demarcated red area on the white of the eye. It often looks dramatic but is usually harmless. ## Triggers Coughing, sneezing, straining, minor trauma, or…"
url: "https://bluefinvision.com/knowledge-base/topics/symptoms-signs/what-causes-subconjunctival-bleeding/"
updated: "2026-01-26"
category: "Symptoms & Signs"
---

# What causes subconjunctival bleeding?

[Subconjunctival bleeding](https://bluefinvision.com/blog/why-a-sudden-blood-red-eye-looks-frightening-but-is-usually-harmless/) occurs when a small blood vessel breaks under the conjunctiva, creating a sharply demarcated red area on the white of the eye. It often looks dramatic but is usually harmless.

## Triggers

Coughing, sneezing, straining, minor trauma, or rubbing the eye commonly cause these haemorrhages. Blood thinners, hypertension, fragile vessels in diabetes, and bleeding disorders increase risk.

- Vision is typically unaffected and there is little or no discomfort
- The patch may change colour like a bruise over one to two weeks
- Recurrent or bilateral episodes raise suspicion of systemic issues
- Significant trauma can be associated with deeper ocular injuries

## Management

No specific treatment is needed in most cases; the blood reabsorbs spontaneously. Assessment is advisable after injury or when episodes are frequent.

- Artificial tears can ease mild irritation
- Blood pressure and medications should be reviewed in recurrent cases
- Protective eyewear helps prevent traumatic episodes
- Seek urgent care if haemorrhage follows significant blunt or penetrating trauma