A sudden, bright red patch on the white of the eye is often described as a “popped” blood vessel. Medically, this condition is known as a Subconjunctival Hemorrhage (SCH) and is generally harmless. It results from the rupture of a small blood vessel on the eye’s surface, leading to a visible accumulation of blood. Although alarming in appearance, an SCH rarely affects vision, causes pain, or indicates a serious problem within the eye itself.
Understanding What Happens
The eye’s visible surface is covered by the conjunctiva, a thin, clear membrane containing numerous delicate capillaries. These vessels are situated just above the sclera, the white layer that forms the eyeball’s structural wall. An SCH occurs when one of these superficial capillaries breaks, causing blood to leak into the space beneath the conjunctiva. Because the conjunctiva is clear and the blood is trapped against the white sclera, the resulting red patch appears intensely bright and sharply demarcated. The anatomical confinement prevents the blood from spreading into deeper structures, such as the iris or cornea, meaning vision remains unaffected. Symptoms are typically limited to the visual presence of the red patch, sometimes accompanied by a mild feeling of grittiness or irritation.
Acute Physical Stressors
The most frequent causes of an SCH are sudden, sharp increases in pressure within the veins of the head and neck. This rapid pressure spike can overwhelm the wall of a superficial capillary, causing it to rupture. Actions that involve intense straining are common acute stressors. Violent sneezing, forceful coughing, and episodes of vomiting all create a powerful pressure surge. Similarly, strenuous activities like heavy lifting, or straining during a bowel movement, utilize the Valsalva maneuver, which momentarily raises internal body pressure and can trigger a vessel break. Minor trauma, such as rubbing the eye too vigorously or a slight bump to the orbital area, can also compromise the integrity of these vessels.
Underlying Systemic Factors
While acute straining is a common trigger, certain underlying health issues can make a person more susceptible to recurring hemorrhages. Chronic conditions that compromise the health of small blood vessels can increase the fragility of the conjunctival capillaries. High blood pressure (hypertension) is a significant factor because it places persistent stress on vessel walls, potentially leading to changes that predispose them to rupture. Diabetes mellitus can also lead to weakened microvasculature, increasing the risk of vessel damage. Furthermore, the use of certain medications is another common systemic contributor. Blood-thinning drugs, such as anticoagulants like warfarin or antiplatelets like aspirin, impede the body’s natural clotting process. This means a minor vessel rupture will lead to a larger, more noticeable hemorrhage. Rarely, underlying clotting disorders may be the reason for frequent, unexplained SCHs.
Expected Resolution and Warning Signs
A subconjunctival hemorrhage is a self-limiting condition that requires no specific medical treatment, as the body naturally reabsorbs the pooled blood. The resolution process is similar to that of a bruise on the skin; the bright red color will gradually fade and may turn a yellowish tint as the hemoglobin breaks down. Most hemorrhages clear within one to two weeks, with larger patches sometimes taking up to three weeks for resolution. Although an SCH is typically benign, certain accompanying symptoms suggest the issue is not a simple broken vessel and requires prompt medical evaluation. If the red patch is accompanied by actual eye pain, a noticeable change in vision, or a watery or pus-like discharge, a different condition may be present. Recurrent hemorrhages that happen frequently without an identifiable cause, or those that occur following a significant head or eye injury, warrant an examination to rule out underlying systemic disorders or more serious ocular trauma.