Skip to Main Content

Thrombocytopenia (Low Platelets)

What is thrombocytopenia?

Thrombocytopenia is a condition that causes low numbers of platelets (thrombocytes). Platelets are blood cells that help the blood to form clots and stop bleeding. If a person has too few platelets, they can bleed or bruise more easily.

Low platelet counts often occur as a side effect of chemotherapy, radiation therapy, certain medications, and other treatments. 

A normal platelet count is 150,000 to 400,000 per microliter of blood. But this can depend on your child's age. Ask your care team what a normal platelet count is for your child.

Platelet Count Range

What it Means

150,000 – 450,000 / microliter Normal platelet count
50,000 – 100,000 / microliter Minor risk for bleeding with injury
Less than 50,000 / microliter Increased bruising
Less than 20,000 / microliter At risk for spontaneous bleeding
Less than 10,000 / microliter At risk for serious bleeding

Symptoms of thrombocytopenia

Mild thrombocytopenia may not cause noticeable symptoms. Or your child may bruise more easily or bleed longer after a cut or injury.

Other signs and symptoms of thrombocytopenia include:

  • Feeling tired
  • Nose bleeds
  • Bleeding gums
  • Heavy menstrual periods or periods that last longer than normal
  • Blood in urine (pee)
  • Stool (poop) that is black or bloody
  • Blood in vomit 
  • Bleeding from the vagina when not having a menstrual period
  • Bad headaches
  • Vision changes
  • Feeling confused or sleepier than usual
  • Purpura: bruising or purplish spots on the skin, lips, or inside the mouth
  • Petechiae: small red or purple “pinpoint” dots on the skin that may look like a rash

Tell the care team right away if your child shows any new or worsening signs of bleeding. 

Graphic of petechiae, which are small red or purple pinpoint dots on the skin that can look like a rash.

Petechiae are flat, rash-like dots on the skin due to bleeding.

Causes of thrombocytopenia

Thrombocytopenia is a common side effect of medical treatments, like chemotherapy, radiation, and certain medicines. It can also occur after blood loss from injury or surgery. 

Causes of low platelets include:   

Diagnosis of thrombocytopenia  

Thrombocytopenia is diagnosed based on your child’s medical history, physical exam, and lab tests. Your doctor may ask you about any changes in bleeding or bruising, recent illnesses, or medicines your child is taking.

Lab tests may include:

  • Complete blood count (CBC) to measure the number and size of platelets and other blood cells
  • Peripheral blood smear to check the shape and size of platelets and other blood cells under a microscope
  • Urine and stool tests to check for blood in the urine or stool
  • Bone marrow aspiration and biopsy to see if are being made normally
  • Blood clotting tests (also called a coagulation panel) to see how well the blood clots how long it takes  

Your care team may do other tests to look for other medical conditions or underlying causes of bleeding.

Treatment of thrombocytopenia

Not all children need treatment for low platelets. Your care team will check your child’s blood counts and monitor symptoms to see when and if treatment is needed.

If thrombocytopenia occurs as a treatment side effect, platelet counts will usually return to normal after the treatment is complete.

Treatments for thrombocytopenia include:

  • Treating the cause: For example, if low platelets are caused by a medical condition, treating that condition might solve the problem. 
  • Platelet transfusion: A transfusion of donor platelets can be given through a vein to replace lost platelets.  
  • Medicines: Your care team might prescribe medicines to help the body make more platelets, decrease the immune response, or control bleeding.
  • Splenectomy: Surgery to remove the spleen might be used if other treatments don’t work. 

How to manage thrombocytopenia

When your child’s platelet counts are low, it is important to take steps to prevent bleeding and bruising. 

  • Avoid certain medicines and supplements. This includes over-the-counter drugs like aspirin and ibuprofen, which can increase bleeding risk. Ask your care team for a list of what to avoid.
  • Brush teeth gently with a soft toothbrush.
  • Avoid activities or sports that have a higher risk of falls or injury.
  • Do not take your child’s temperature rectally.
  • Have your child wear shoes, even when inside.
  • Be extra careful when using sharp objects. If your child is older, they should use an electric razor to shave.
  • Use lotion and lip balm to prevent dry skin and chapped lips.
  • Be sure your child does not pick at scabs or pimples.
  • Females who have a menstrual cycle should use sanitary pads instead of tampons. 

How to treat minor bleeding at home

Daily activities can cause bleeding or bruising. Use the following tips to care for your child at home.

  • Minor cuts and wounds: Use a clean cloth to apply pressure to the wound until bleeding stops. Clean the wound with soap and water. Dry the area and apply a sterile bandage or gauze.
  • Bleeding in the mouth or gums: Rinse your child’s mouth with ice or cold water. Follow your care team’s instructions for oral care to help prevent bleeding gums.
  • Nosebleeds: Have your child sit up straight and lean slightly forward. Apply pressure to the outside of each nostril, just below the bridge of the nose. Pinch the area with the thumb and finger and hold gentle pressure for 5–10 minutes. Release pressure slowly to see if bleeding has stopped.
  • Bruising: Apply ice to the area for about 20 minutes.

If bleeding is heavy or does not stop, seek medical care right away.

 Questions to ask the care team

  • What is the cause of my child’s low platelet count?
  • What is my child’s risk of bleeding?
  • How often will my child need tests to monitor their platelet counts?
  • Should my child avoid certain activities while their platelet counts are low?
  • Are there other precautions to take to prevent bleeding?
  • What signs of bleeding should we watch for?

Key points about thrombocytopenia

  • Thrombocytopenia, or low platelets, is a common side effect of some treatments including chemotherapy, radiation therapy, and certain medicines.
  • Thrombocytopenia can also be caused by an underlying medical condition.  
  • If your child has low platelet counts, they can bleed or bruise more easily. 
  • Most thrombocytopenia is temporary and may not need treatment. Your care team will let you know what tests and treatment your child needs.
  • Talk to your care team about how to reduce your child’s risk of bleeding and what to do if bleeding occurs.


Reviewed: September 2024

Related Content