Low Platelet Count (Thrombocytopenia)

Author: Karen Arnold-Korzeniowski, BSN RN
Content Contributor: Allyson Van Horn, MPH
Last Reviewed: January 13, 2026

Platelets are blood cells that help your body clot and stop bleeding. A low platelet level is called thrombocytopenia. Cancer and some of its treatments can damage platelets and cause thrombocytopenia. If you are getting radiation or chemotherapy, you are at higher risk of thrombocytopenia.

Your risk of bleeding is higher with thrombocytopenia. If you have a low platelet count, avoid any activities that could lead to bleeding. Minor injuries, such as a small cut or bump, can cause too much bleeding when your platelets are low.

A normal platelet count range is 150,000 to 400,000 per cubic millimeter (mm3) of blood (some providers prefer an upper range of 450,000 per mm3). During treatment, your platelet count may drop. Your platelet count will be checked with blood tests as needed. Any time your platelet count drops below 50,000 per mm3, you are at a greater risk for bleeding. You may need a platelet transfusion if your platelet count drops below a safe level.

What are the signs of thrombocytopenia?

While getting certain treatments, there is nothing that you can do to prevent thrombocytopenia. Your providers will keep an eye on your levels during and after your treatment. Some signs of thrombocytopenia are serious. Call your provider right away if you have: 

  • A lot of bruising on your skin.
  • Tiny, pinpoint red spots on your skin called petechiae.
  • Bleeding gums.
  • Nosebleeds that won't stop.
  • A lot of bleeding from a small cut, or bleeding that won't stop even after pressure has been put on the cut or bleeding area.
  • Dark-colored urine or blood in your urine.
  • Blood from your rectum, blood in your stool, or black-colored stool.
  • Menstrual bleeding that is heavier than usual, lasts longer than usual, or happens between periods.

What can I do to prevent bleeding if I have thrombocytopenia?

  • Keep your mouth clean and moist.
  • Brush your teeth gently with a soft bristle toothbrush. If you cannot use a toothbrush, use a sponge toothette to clean your teeth and gums.
  • Rinse your mouth after each meal with a baking soda solution (2 teaspoons baking soda to every 8 ounces water).
  • Do not use dental floss.
  • Do not use mouthwashes that have alcohol in them. Alcohol can dry out your mouth, which may lead to bleeding.
  • Use petroleum jelly or other lip balms to keep your lips moist and to prevent cracking.
  • Take sips of water or juice often if your tongue or mouth feels dry.
  • Modify feminine hygiene practices:
    • Use sanitary napkins rather than tampons during menstruation.
    • Avoid vaginal douching.

Other things you can do to prevent bleeding:

  • Do not cough hard. If you have a cough, ask your provider if you can take cough medicine.
  • Do not blow your nose too hard.
  • Try to not push hard with bowel movements. If you are constipated, take a stool softener or laxative to make it easier.
  • Do not use rectal thermometers, suppositories, or enemas.
  • Use an electric razor for shaving.
  • Do not have any dental work or cleaning before talking to your provider.
  • Do not take any medications that affect blood clotting. These medications include:
    • Aspirin or anything that contains aspirin. Check the labels of all drugs you are taking for salicylic acid, the chemical name for aspirin. If you are not sure about a drug or cannot tell by reading the label, check with your provider or pharmacist.
    • Non-steroidal, anti-inflammatory medications (NSAIDs) such as Motrin/Advil (ibuprofen), Aleve (naproxen), Celebrex (celecoxib), etc.

Lifestyle changes to lessen the risk of bleeding:

  • Avoid strenuous activity and lifting heavy objects.
  • Avoid sports and activities that could lead to falling and/or injury, like bike riding, rollerblading, skating, and skiing.
  • Drink 8 to 10, 8-ounce glasses of non-alcoholic fluid a day to keep your mouth moist, to avoid constipation, and to keep the intestinal lining working well.
  • Always wear shoes or slippers to protect your feet.
  • Do not wear tight-fitting clothing.
  • Talk to your provider about sexual activity to see if it is safe. They may say you should not have intercourse, as vaginal or anal penetration (including toys/props) or oral sex can pose a risk of bleeding. If your provider tells you that intercourse is safe, you can use a water-based lubricant and avoid thrusting to lower the chance of bleeding.

What if I start to bleed?

Even if you take all precautions, you may still be injured or start to bleed. If bleeding starts, put firm pressure on the area for 5 minutes. If bleeding does not stop after 5 minutes, use pressure until it has fully stopped.

If you have a nosebleed, use pressure with your fingers below the bridge of your nose until the bleeding stops. Keep your head raised.

When should I call my provider?

Call your provider right away if:

  • Bleeding does not stop after you have used pressure for 10 to 15 minutes.
  • You have blood in your urine, or your urine looks dark in color.
  • You see blood coming from your rectum, have blood in your stool, or if your stool is black.
  • You have vision changes.
  • You have a headache that won’t go away or a change in your level of consciousness, such as trouble paying attention, sleeping more than usual, confusion, and/or trouble being woken up.

If you have an injury or start bleeding for no reason, call 911 right away. Tell the provider that you are being treated for cancer and that your platelet count may be low.

How is thrombocytopenia treated?

You may need a transfusion of platelets. These transfusions are most often done in an outpatient treatment center. Patients rarely have to be admitted to the hospital just to get platelet transfusions.

Your provider may decide to delay cancer treatments until your platelet count has returned to normal levels.