What should parents look for when their children take blood thinners for blood clots?

When your child takes blood thinners, it lowers the risk of new blood clots. However, it does not lower the risk to zero. You need to look for new signs and symptoms of blood clots, or signs and symptoms that get worse.
  • If you see new signs and symptoms of blood clots as described above, or if the signs and symptoms get worse, it could mean your child has a new blood clot.

  • You need to seek prompt medical attention for new or worse symptoms of blood clots.
You also need to look for signs of bleeding. When your child is on blood thinners:
  • Small cuts on the skin will ooze more than usual;

  • Nose-bleeds can occur more frequently or last longer;

  • Bruises in areas of injury occur more easily and tend to grow larger; and

  • Teenage girls and young women may have heavier periods.

If your child bleeds often, you should contact your doctor. If your child becomes pale or tired or bleeds for a long time, you must seek prompt medical care.

You and your child should talk with your hematologist about what to do when bleeding starts, and when you should seek prompt medical care.

Can children on blood thinners participate in the regular activities that children do?

You and your child should talk to your pediatric hematologist about specific activity limits.

  • Your child should avoid activities that are high-risk for injury – especially head injury.

  • In general, your child should avoid high-impact sports like American football, ice hockey, etc.

  • Your child should always wear seat belts in motor vehicles.

  • Your child should wear helmets on bikes and skateboards.

  • Your child’s hematologist will help decide with you whether your child needs other activity limits. You and your doctor will need to think about your child’s:

    • Age, development and judgment

    • Coordination and history of injuries, and

    • Skill with a particular activity

  • Activities supervised by an adult tend to decrease the risks of injury and bleeding.

  • However, to reduce the risk of new blood clots, children must stay active. So, while on anti-clotting medications:

    • Your child can and should still participate in regular exercise.

    • For example, age-appropriate, supervised, low-impact/low-injury-risk sports, such as walking, swimming, and biking on a well-paved surface while wearing a helmet can help lower the risk of blood clots.


Neil A. Goldenberg, MD, PhD

Associate Professor of Pediatrics and Medicine, Johns Hopkins University School of Medicine,
Baltimore, MD, USA

Chief Research Officer and Director, Thrombosis Program,
All Children’s Hospital Johns Hopkins Medicine and All Children’s Research Institute,
St. Petersburg, FL, USA     March 2014

Download: Blood Clots and Children Resource PDF

Blood Clots in Children

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