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Bruising and Bleeding Problems
Some types of cancer and cancer treatment can cause bruising and bleeding problems. Learn why you might bruise or bleed more easily, what to watch for, and when to get help.
What do cancer bruises and bleeding look like?
Cancer-related bruises and bleeding are similar to normal bruising and bleeding, except they might happen more often and without a known reason.
This can look like:
- Bruises: A collection of blood under your skin (ecchymosis). It starts out black and blue and gradually fades to brown, green, and yellow as it heals. You can get bruises anywhere on your body.
- Hematomas: A collection of clotted blood, either on your skin or inside your organs. (A bruise is a hematoma just under your skin.) A hematoma usually goes away on its own, but it may need to be drained if it’s big and causing problems, such as pain.
- Petechiae: Small red or purple dots on your skin, most often found in areas where rubbing or pressure happens. They are another sign of bleeding under your skin.
- Purpura: Areas of bleeding under your skin that happen when multiple petechiae grow together.
What to watch for
Cancer-related bruises and bleeding can be unexpected, sudden, or worse than usual. You might get bruises when you don’t remember bumping into something or hurting yourself.
You also might bleed from body parts and in ways you don’t expect, such as:
- Nosebleeds and bleeding gums
- Bleeding from your rectum
- Blood in your stool (poop) or urine (pee)
- Blood in your sputum (mucus you cough up)
- Blood in vomit (hematemesis) — this can look red or like coffee grounds
- Cuts that bleed too much or for too long
- Menstrual bleeding worse than a normal period
Most of the time, this bleeding will only be a small amount or stop on its own. But if it is a large amount, happens several times, or doesn’t stop, you need to get help right away.
Call 911 or go to the emergency room if:
- You fall or hit your head while your platelets are low
- Your bleeding won't stop
- You have new or worsening confusion
Which cancers can cause bruising and bleeding?
Some types of cancer can increase your risk of bruising or bleeding even before they are diagnosed or treated.
This includes many blood-related cancers, such as:
- Leukemias
- Non-Hodgkin lymphoma
- Multiple myeloma
- Myelodysplastic syndromes (MDS)
- Waldenstrom macroglobulinemia
And some solid tumors (cancers that aren’t blood-related), including:
- Pancreas, kidney, stomach, lung, and brain cancers
- Liver cancer and cancers that have metastasized to your liver,
Why do these problems happen?
You might bruise or bleed more easily if your body isn’t clotting the way it should. Clotting (coagulation) is the way your body stops bleeding.
To clot correctly, your body needs certain types of blood cells and proteins. When there is a problem with these, you are more likely to bruise and bleed. These problems can be caused by certain kinds of cancer, cancer treatment, or other conditions that aren’t cancer.
Words to know
Platelets are the blood cells involved with clotting.
- Low platelet count is called thrombocytopenia.
Clotting factors (or coagulation factors) are the proteins involved with clotting.
- Problems with these are called coagulopathies.
Cancer and thrombocytopenia (low platelet count)
If your platelet count is low or if your platelets aren’t working correctly, you are at higher risk of bruising and bleeding.
Cancers that can cause low platelet counts
Some kinds of cancer and cancer treatment can interfere with your body’s ability to make platelets by affecting the blood-forming cells in your bone marrow.
Cancers that can affect your body’s ability to make platelets include:
- Lymphoma
- Myelodysplastic syndromes (MDS)
- Waldenstrom macroglobulinemia
- Some types of leukemia
- Liver cancer or liver metastases
Liver cancer or liver metastases can cause low platelet counts if it interferes with the way your liver works. If your liver can’t make enough thrombopoietin (a platelet growth factor), your body may not make enough platelets.
Cancer treatments and low platelets
Cancer treatments like chemotherapy (chemo) and radiation therapy can also cause thrombocytopenia by damaging the fast-growing cells that become platelets. Platelet levels (counts) usually hit their lowest point 1 to 2 days after treatment and slowly return to normal over the next several weeks.
Other causes of low platelets
- Medicines: Other medicines can also interfere with the way your platelets work. The medicines that most often cause problems include aspirin, anticoagulants (blood thinners), and nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen.
- Heparin-induced thrombocytopenia: Heparin is a blood thinner used to prevent blood clots. Long-term use can sometimes lower the amount of platelets in your blood.
- Immune problems: Some people with cancer are born with immune problems that can damage the body’s platelets. This includes ITP (immune thrombocytopenia) and lupus (systemic lupus erythematosus).
- Infections: Some people with cancer develop infections that can affect their platelets, such as Epstein-Barr virus (EBV), HIV (human immunodeficiency virus), and other severe infections.
Cancer and coagulopathies (clotting disorders)
Even if your platelet levels aren’t low, you might bruise or bleed more easily for other reasons.
Cancer-related causes of clotting disorders
Some types of cancer can cause coagulopathies that increase your risk of bruises and bleeding.
- Liver cancer, liver metastases, or other liver problems can prevent your liver from making clotting factors and albumin. These proteins help your blood clot. If your liver doesn’t make enough of them, you are more likely to bruise and bleed.
- Acute promyelocytic leukemia (APL) is a type of leukemia that affects a certain kind of blood-forming cell. People with APL are at risk for a condition where the body breaks down blood clots too quickly (hyperfibrinolytic syndrome). This increases the risk of bleeding and bruising.
Acquired hemophilia
People with certain types of cancer can also develop “acquired” forms of some clotting disorders, including acquired hemophilia. Hemophilia is an immune disorder that stops your blood from clotting normally. It is usually passed down from a parent (inherited), but it can also be caused by some types of solid tumors and blood cancers.
Some cancer treatments, such as monoclonal antibodies and immune checkpoint inhibitors, can also cause it. So can penicillin and other antibiotics.
Acquired Willebrand’s disease
Willebrand’s disease is another immune disorder that’s usually inherited but can sometimes be acquired. With this disease, some of your clotting factors could be missing or not working well.
Multiple myeloma, Waldenstrom macroglobulinemia, CLL (chronic lymphocytic leukemia), hairy cell leukemia, and non-Hodgkin lymphoma can all cause this disease. It might also be caused by some of the myeloproliferative neoplasms, such as essential thrombocytopenia.
Cancer medicines and bleeding
Some cancer medicines increase your risk of bleeding in other ways. For example, targeted therapies called angiogenesis inhibitors (anti-angiogenesis drugs) can prevent your body from making new blood vessels. This makes you more likely to bruise or bleed while getting treatment.
How to lower your risk of bleeding
If you are at increased risk of bleeding, there are things you can do to lower your risk.
- Avoid cuts or other injuries. Use a soft toothbrush and an electric shaver (not a razor blade). Be careful when using sharp objects like knives, scissors, or other tools.
- Lower your risk of rectal bleeding. Take steps to prevent constipation and hemorrhoids and don’t put anything into your rectum.
- Avoid nosebleeds. Don’t blow your nose forcefully.
- Ask your cancer care team before taking any new medicines. This includes new prescriptions, over-the-counter medicines, supplements, and vitamins. Some of these can make it harder for your blood to clot.
You can find more information about lowering your bleeding risk in Thrombocytopenia.
When to talk to your doctor about bleeding and bruising
Bleeding can be serious and even life-threatening for some people.
Always tell your doctor or cancer care team if you are bruising or bleeding more easily than you normally do. But in some cases, you need to contact them right away to prevent your problems from getting worse.
Call your doctor or cancer care team right away if you have:
- Dark or bright red vomit
- Red or black stools (poop)
- Dizziness, lightheadedness, or balance problems
- Been in bed for more than 24 hours
Other symptoms of bleeding might be signs of an emergency. If you have bleeding problems and the following happen, get help right away.
Call 911 or go to the emergency room if:
- You fall or hit your head while your platelets are low
- Your bleeding won't stop
- You have new or worsening confusion
Learn more
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- References
Developed by the American Cancer Society medical and editorial content team with medical review and contribution by the American Society of Clinical Oncology (ASCO).
American Society of Clinical Oncology. Bleeding problems. Cancer.net. Content is no longer available.
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Last Revised: July 17, 2025
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