Blood Spots
Blood spots on the skin, also called purpura or petechiae, can often seem alarming when they appear suddenly. Minor injuries or trauma that break small blood vessels most commonly cause these spots, but sometimes they signal an underlying health problem, such as a blood clotting disorder, vitamin deficiency, or an immune condition.
People may also notice blood spots after activities that cause increased pressure, like heavy lifting or persistent coughing. Knowing what could cause blood spots helps people decide if it’s a harmless change or something that needs a doctor’s attention.
Definition of Symptom
Blood spots on the skin are small areas where blood leaks out from tiny blood vessels called capillaries. These spots can be red, purple, or brown and may show up anywhere on the body. People often see them as petechiae, purpura spots, or larger bruises (ecchymoses).
Petechiae are very tiny red or purple dots, usually less than 2 millimeters in size. Purpura are bigger than petechiae but smaller than bruises. Bruises, or ecchymosis, are larger areas of blood under the skin. These marks happen when capillaries or other small blood vessels break and allow blood to pool under the surface of the skin. Some important differences:
| Symptom | Description | Size |
|---|---|---|
| Petechiae | Tiny red or purple dots | < 2 mm |
| Purpura | Red-purple patches or spots | 2 mm–1 cm |
| Ecchymosis | Larger bruise-like areas | > 1 cm |
| Hematoma | Swollen, raised collection of blood under the skin | Varies |
Blood spots are not the same as simple redness (erythema), which does not come from bleeding under the skin. Blood spots are usually flat and do not fade when pressed. If a spot or bruise appears with no known injury, it can be a sign of changes in blood vessels or problems with how the blood clots.
Possible Causes/Diseases Condition
Different medical issues can cause blood spots on the skin. Some conditions are mild, while others can be serious. Purpura describes purple, red, or brown skin spots caused by bleeding under the skin. It is a sign, not a disease, and may indicate several medical conditions.
Common Causes of Blood Spots
| Cause | Description |
|---|---|
| Injury or Trauma | Bumping or injuring the skin. |
| Thrombocytopenia | Low platelet count affects blood clotting. |
| Thrombocytopenic Purpura | Type of purpura linked to low platelets. |
| Nonthrombocytopenic Purpura | Purpura not related to platelet count changes. |
| Vasculitis | Inflammation of blood vessels. |
| DIC (Disseminated Intravascular Coagulation) | A severe blood clotting disorder. |
| Liver Disease | Affects normal blood clotting. |
| Bone Marrow Disorders | Can lower blood cell production. |
| Cancer | Some cancers affect blood cells and clotting. |
| Autoimmune Diseases | Conditions like lupus can damage blood vessels. |
| Scurvy | Caused by vitamin C deficiency, leading to bleeding. |
Certain infections, such as rubella, cytomegalovirus, and strep throat, can also cause blood spots. Some viral infections affect how blood clots or damage blood vessels. If someone has had their spleen removed (splenectomy), their risk for blood spots can increase because it affects blood cell function. Some medications and allergic reactions can make blood vessels fragile or lower platelet counts, raising the risk of blood spots.
Other Non-Disease Causes
Not all blood spots are linked to underlying diseases. Many appear after everyday activities or due to outside influences. Minor trauma often causes blood spots. Bumping against hard surfaces or squeezing the skin can break small blood vessels (capillaries), leading to red or purple spots. These usually fade with time.
Medications like aspirin, ibuprofen, and blood thinners such as warfarin can increase the risk of capillaries breaking. Even corticosteroids or chemotherapy drugs may weaken blood vessels and cause spots. Here’s a quick look at some non-disease triggers:
| Cause | Examples |
|---|---|
| Physical injury | Sports, falls, bumping into objects |
| Medications | Aspirin, ibuprofen, steroids, blood thinners |
| Dietary causes | Low vitamin C or vitamin K |
| Medical treatments | Chemotherapy, blood transfusions, IVIG |
| Stress and fatigue | Both may make skin more sensitive or fragile |
Low vitamin C (scurvy) can make blood vessels more fragile, causing blood spots. Vitamin K is important for normal blood clotting, and a lack of it can cause spots to form easily. Medical treatments like blood transfusions, IVIG, or certain growth factors have also been linked to blood spots in some people. Even high levels of physical or emotional stress and fatigue can sometimes play a part, though this is less common.
How It Causes the Symptom
Blood spots, or purpura, appear when small blood vessels under the skin burst. The leaked blood pools just beneath the skin, creating red, purple, or brown spots. A drop in platelet counts is a key reason these blood vessels may leak. Platelets help blood clot. When there are not enough platelets, the blood cannot clot well, and bleeding under the skin is more likely.
Sometimes, the immune system attacks and destroys platelets by mistake. This can lower platelet numbers and lead to blood spots. A problem with the body’s clotting system can also cause blood spots. If the proteins needed for clotting are missing or not working, even small injuries may cause bleeding beneath the skin.
Doctors often order a complete blood count (CBC) to help find the cause of blood spots. This test checks platelet levels and other important blood cells.
| Cause | How It Affects Blood Spots |
|---|---|
| Low platelet count | Less clotting, more bleeding under skin |
| Immune system attacks platelets | Platelets destroyed, increased bleeding risk |
| Problems with clotting proteins | Poor healing, more blood escaping vessels |
Possible Complications
Blood spots on the skin, such as purpura or petechiae, are often harmless. However, complications can happen, especially if an underlying health problem is present. Excessive bleeding can occur if blood spots come from a blood clotting problem. In these cases, people may bruise easily or bleed more than normal from minor cuts.
Infections may develop if the immune system is weak or if the skin is broken near blood spots. This can lead to redness, swelling, or pus. If an allergy causes blood spots, severe reactions such as anaphylaxis can develop. This is a medical emergency and needs quick treatment.
Malnutrition, especially lack of vitamins B12, C, K, or folate, can make complications worse. Low vitamin levels may slow down healing and increase the risk of new spots or uncontrolled bleeding. A variety of complications and possible signs to watch for include:
| Complication | Possible Signs |
|---|---|
| Excessive bleeding | Prolonged or heavy bleeding, easy bruising |
| Infection | Redness, warmth, pus, or fever |
| Anaphylaxis | Swelling, tight throat, trouble breathing |
| Healing problems | Slow recovery, frequent new spots |
When to Seek Medical Attention
Watch for certain signs if you notice blood spots on the skin. While small spots from minor injuries are often harmless, some cases need professional care. Contact a healthcare provider if blood spots:
- Appear suddenly and there are many new spots.
- Spread or increase in number quickly.
- Do not link to a known injury.
Never ignore certain symptoms. Seek medical help right away if blood spots come with:
- Fever or chills
- Unexplained bruising
- Severe headaches or confusion
- Dizziness or trouble breathing
- Pain or swelling in the affected area
| Symptom | Medical Attention Needed? |
|---|---|
| Fever | Yes |
| Rapid spot increase | Yes |
| Confusion or dizziness | Yes |
| Mild, one-time spot | Usually not |
| Unexplained bleeding | Yes |
See a healthcare provider if the blood spots do not go away, get worse, or appear after starting new medications. Watch children and people with weak immune systems closely.
