A bruise is a common skin injury occurring when small blood vessels beneath the skin break. Blood leaks into surrounding tissues, causing visible discoloration. The bruise’s appearance changes as the body reabsorbs the pooled blood. Initially, it often appears reddish or darker, then progresses to shades of blue, purple, or black within a day or two. As healing continues, it may turn greenish-yellow before fading completely, usually within a few days to several weeks, depending on its severity.
The Link Between Bruises and Scars
Typical bruises do not result in scars because they primarily involve damage to blood vessels and soft tissues beneath the skin, not the deep layers of the skin itself. True scars form when the dermis, the deeper layer of skin, is significantly injured and replaces normal skin tissue with fibrous tissue during repair. Since bruises usually do not cause this type of deep dermal damage, they generally resolve without leaving a permanent textural change.
However, a bruise might leave a lasting mark distinct from a true scar: post-inflammatory hyperpigmentation. This discoloration occurs when the body’s healing process leaves behind excess melanin, the pigment that gives skin its color. This type of discoloration is more common in individuals with darker skin tones, where bruises may appear as darker brown or black areas that gradually lighten. True scarring from a bruise is rare, typically occurring only with significant trauma causing a deep wound (like a laceration) or repeated injury to the same area, leading to chronic inflammation and tissue disruption.
Minimizing Scarring Risk and What to Expect
Initial care can help minimize lasting marks from a bruise. Apply an ice pack wrapped in a thin towel to the affected area for about 20 minutes, several times for a day or two after the injury, to reduce swelling and pain. Elevating the bruised area above heart level, if possible, also aids in reducing swelling. Avoid picking or scratching the bruised area, as this can introduce infection or further damage the skin, potentially prolonging healing.
Protecting the bruised area from sun exposure is advisable, especially if post-inflammatory hyperpigmentation is a concern, as sun exposure can darken existing discoloration. Most bruises resolve completely without any permanent trace within two weeks. Seek medical attention if:
A bruise is extremely large or painful.
There are signs of infection, such as increasing redness or warmth.
A lump forms over the bruise.
A mark persists for an unusually long time, such as several weeks without improvement.