Those tiny purple dots inside or around a bruise are called petechiae, and they form when the smallest blood vessels in your skin, called capillaries, break and leak tiny amounts of blood into the surrounding tissue. Each dot is only about 1 to 2 millimeters across. In most cases, they appear alongside a bruise because the same impact that caused the larger bruise also ruptured nearby capillaries at the surface level of your skin.
What Petechiae Actually Are
Your skin contains a network of increasingly tiny blood vessels. The smallest of these, capillaries, are so narrow that blood cells pass through them in single file. When force damages an area of tissue, some of these capillaries rupture. The larger pooling of blood underneath creates the familiar bruise (medically called ecchymosis), while individual pinpoint capillary breaks at the surface create those distinct dots.
The dots look purple or deep red because you’re seeing a tiny pocket of blood just beneath the skin’s outer layer. On darker skin tones, they may appear dark brown or nearly black. One easy way to tell petechiae apart from a rash: press on them with your finger. Petechiae don’t fade or turn white when you press. A rash typically does. That’s because the color comes from blood trapped outside the vessel, not from blood still flowing through it.
Why They Show Up Inside a Bruise
The most common reason is simply the force of the original injury. A hard bump, fall, or pinch can break blood vessels at multiple depths simultaneously. The deeper bleeding spreads into a wide bruise, while shallow capillary breaks create scattered dots on the surface. You’re seeing two layers of the same injury.
Sometimes the dots appear a day or two after the bruise itself. This can happen because swelling and pressure from the initial bruise damage neighboring capillaries that weren’t hurt in the original impact. Think of it as secondary breakage: the bruised tissue becomes congested, and fragile capillaries in the area give way under the added pressure.
Straining can also produce petechiae without any direct hit. Intense coughing, vomiting, heavy lifting, or even childbirth can spike pressure in small blood vessels enough to rupture them. If you notice dots on your face, neck, or chest after a bout of vomiting or a hard workout, that pressure spike is the likely cause.
When Dots Signal Something Else
Most of the time, petechiae inside a bruise are harmless and heal on their own. But scattered petechiae that appear without an obvious injury, or that keep showing up in new places, can point to an underlying issue worth investigating.
Low platelet counts are one of the more common medical causes. Platelets are the blood cells responsible for plugging broken vessels and starting the clotting process. When platelet levels drop into a certain range, the body loses some of its ability to seal off even routine capillary damage, and petechiae start appearing with little or no trauma. People on blood-thinning medications or drugs that affect platelet function are at higher risk for this kind of easy bleeding.
Vasculitis, an inflammation of blood vessel walls, is a less common but more serious possibility. In vasculitis, the immune system attacks blood vessels, weakening them and causing leaks. The spots it produces sometimes feel slightly raised or bumpy to the touch, which distinguishes them from the flat dots of ordinary petechiae. They may also appear alongside open sores or lumps on the skin.
How These Bruises Heal
Petechiae are small enough that your body reabsorbs the leaked blood relatively quickly, often within a few days to a week. The bruise underneath follows a slower, more visible progression. It typically starts red or purple, then shifts to blue, then greenish-yellow, and finally fades to light brown before disappearing. Most bruises resolve completely within two weeks. More severe ones, especially those with significant swelling or a hematoma (a firm lump of collected blood), can take a month or more.
You can speed things along slightly by icing the area in the first day or two to limit swelling, then switching to gentle warmth after 48 hours to encourage blood flow and reabsorption. Keeping the bruised area elevated when possible also helps reduce pooling.
Signs That Deserve Attention
A bruise with dots from a known bump or fall, with no other symptoms, is rarely a concern. But certain patterns suggest your body may be having trouble with clotting or blood vessel integrity:
- Petechiae without trauma: Dots appearing on skin that wasn’t injured, especially in clusters on the legs, torso, or inside the mouth.
- Frequent or oversized bruises: Bruising easily from minor contact, or bruises that seem disproportionately large compared to the bump that caused them.
- Fever alongside the dots: This combination can indicate an infection affecting your blood or blood vessels.
- Bleeding from other sites: Nosebleeds, bleeding gums, or blood in urine or stool occurring at the same time as unexplained petechiae.
- Dots that spread rapidly: New petechiae appearing over hours rather than days, especially with feeling generally unwell.
Any of these patterns warrants a blood test to check your platelet count and clotting function. The test is simple and quick, and it can rule out or catch problems early.