Bleeding in the Mouth

Bleeding in the mouth is often caused by mouth sores, gum (periodontal) disease, or by a low platelet count (cells that help the blood clot). Low platelet counts can be a side effect of chemo or radiation treatment.

Everyday actions such as brushing or flossing teeth can cause bleeding. Side effects of chemo or radiation can include dry mouth or mouth sores, which can bleed.

What to look for

  • Blood or bruises in mouth (from or on the gums, tongue, etc.)
  • Rash or bright red pinpoint-sized dots on tongue, under tongue, on roof of mouth, and/or on inside of cheeks
  • Blood oozing from mouth

What the patient can do

  • Rinse your mouth gently with ice water every 2 hours.
  • Suck on ice chips. (Avoid hard candies if your mouth is bleeding.)
  • Rinse your mouth or brush your teeth with a soft toothbrush after eating. Rinse the toothbrush in hot water to soften the bristles even more.
  • Use soft foam mouth swabs or gauze wrapped around a Popsicle stick or tongue depressor to clean teeth if a soft toothbrush causes bleeding.
  • Avoid store-bought mouthwash. See Dry Mouth to learn how to make a gentle mouth rinse.
  • Eat foods that are soft, smooth, and high in calories and protein. Refrigerated soft foods, such as ice cream, applesauce, puddings, and yogurt, can help because cold helps to slow the bleeding.
  • Puree hard foods, such as apples, pears, etc., in the blender.
  • Avoid hot drinks, such as coffee and tea. Heat enlarges blood vessels and can make bleeding worse.
  • Put cream or salve on your lips to prevent dryness.
  • If you wear dentures, keep them out of your mouth, especially if they don’t fit well.
  • Avoid aspirin products. Check labels of over-the-counter drugs to be sure they don’t contain aspirin, or check with your pharmacist.

What caregivers can do

  • Offer the patient cold water mouth rinses before each meal. Keep ice water nearby.
  • If the mouth is oozing blood, keep a bowl nearby for spitting out mouth rinses.
  • Make milkshakes or smoothies in the blender, and offer other soft frozen treats.
  • Avoid nuts, sharp or crunchy foods (such as chips or crackers), and foods with hard coatings.
  • Freeze a few wet tea bags, and have the patient press one on any bleeding area.

Call the cancer team if the patient:

  • Is bleeding from the mouth for the first time
  • Has bleeding that lasts for more than a half-hour
  • Vomits blood or material that looks like coffee grounds
  • Feels light-headed or dizzy

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master’s-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

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Last Medical Review: June 8, 2015 Last Revised: June 8, 2015

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