Petechiae (pronounced peh-TEE-kee-ee) are tiny red, purple, or brown dots on the skin caused by bleeding from broken capillaries. Each spot is typically smaller than 2 millimeters, about the size of a pinpoint. They’re flat to the touch, don’t itch, and won’t fade when you press on them. That last detail is the key feature that separates petechiae from ordinary redness or a simple rash.
Why They Don’t Fade Under Pressure
Most red marks on the skin are caused by blood flowing through dilated vessels. Press on them and the blood moves away temporarily, making the spot disappear for a moment. Petechiae are different. The blood has already leaked out of the capillaries and is sitting in the surrounding tissue. Pressing a glass or clear plastic against the skin (sometimes called a “glass test” or “tumbler test”) compresses the vessels underneath, but the escaped blood has nowhere to go. The dots stay visible. This is what doctors mean by “non-blanching,” and it’s the simplest way to tell petechiae apart from a harmless flush or heat rash.
Petechiae vs. Purpura vs. Bruises
All three involve blood leaking under the skin, but they differ in size. Petechiae are the smallest, appearing as pinpoint dots. Purpura describes larger flat areas of bleeding, typically a few millimeters to about a centimeter across. Ecchymosis is the medical term for what most people call a bruise: a broad, discolored patch where a larger volume of blood has pooled under the tissue. Seeing a few petechiae after straining or coughing hard is common and usually harmless. Widespread purpura or unexplained bruising is more likely to signal an underlying problem.
Common, Harmless Triggers
Petechiae often show up in situations where small blood vessels face sudden pressure. Hard coughing, vomiting, or straining during childbirth can cause them to appear on the face, especially around the eyes and on the cheeks, where the skin is thin. Crying hard enough to raise pressure in the head can do the same thing, which is why parents sometimes notice them on a toddler’s face after a prolonged tantrum.
Tight clothing, tourniquets (like the band wrapped around your arm during a blood draw), or even vigorous scratching can rupture capillaries locally. Sunburn and aging also weaken capillary walls, making them more prone to tiny leaks. In all these cases, the dots tend to be limited to one area and fade on their own within a few days as the body reabsorbs the blood.
When Petechiae Point to Something Serious
Petechiae that appear without an obvious physical trigger, spread across larger areas of the body, or show up alongside a fever deserve prompt attention. The two broad categories of serious causes are low platelet counts and infections.
Low Platelet Counts
Platelets are the blood cells responsible for plugging tiny leaks in vessel walls. A normal count ranges roughly from 150,000 to 400,000 per microliter of blood. When counts drop below about 50,000, people often notice easy bruising, petechiae, and prolonged bleeding from minor cuts. Below 20,000, spontaneous bleeding becomes a real risk. Conditions that can lower platelet counts include immune disorders where the body destroys its own platelets, bone marrow problems, certain viral infections, and some medications, particularly blood thinners and drugs used in chemotherapy.
Infections
Certain bacterial and viral infections can damage blood vessels directly or trigger the immune system in ways that cause widespread capillary bleeding. The most urgent example is meningococcal disease, a bacterial infection that can invade the bloodstream, damage blood vessels, and cut off oxygen to tissues. The rash it produces can start as tiny pinpoint dots and rapidly expand into larger bruise-like patches. Other warning signs include high fever, severe headache, stiff neck, sensitivity to bright light, confusion, and joint or muscle pain. This condition worsens fast, and early treatment dramatically improves outcomes.
Nutritional Deficiencies
Vitamin C is essential for building collagen, the protein that gives structure and strength to blood vessel walls. When vitamin C levels are severely low (a condition historically known as scurvy), capillaries weaken and begin to leak, producing petechiae along with bleeding gums, joint pain, and poor wound healing. This is uncommon in developed countries but still occurs in people with extremely limited diets, certain eating disorders, or conditions that impair nutrient absorption. Notably, standard blood clotting tests come back normal in vitamin C deficiency because the problem isn’t with clotting itself. It’s with the vessels being too fragile to hold blood in.
How Petechiae Are Evaluated
If you visit a doctor about unexplained petechiae, the first step is usually a complete blood count to check your platelet level. That single test can quickly confirm or rule out one of the most common causes. Beyond that, your doctor will look at the pattern: where the dots are, how many there are, whether they’re spreading, and what other symptoms you have. Petechiae limited to the face after a bout of vomiting tell a very different story than petechiae scattered across the legs and torso with a fever.
In children, petechiae combined with a fever are taken especially seriously. Pediatric guidelines recommend that any child with both symptoms be evaluated quickly by an experienced clinician, because the overlap between a harmless viral illness and early meningococcal disease can be hard to distinguish without testing. For newborns, any petechiae at all typically warrant a prompt medical review.
What to Watch For
A few dots near your eyes after throwing up or coughing violently are almost always benign and will resolve on their own. The picture changes if petechiae appear without a clear reason, increase in number over hours, or come with fever, fatigue, unexplained weight loss, or unusual bleeding from gums or the nose. Rapidly spreading spots that grow into larger purple patches are the most urgent scenario, particularly in children, and call for immediate evaluation.