International Hemophilia Day — Information from AboutKidsHealth

April 17 is International Hemophilia Day. Learn more about hemophilia—a rare inherited condition that affects the blood’s ability to clot properly—from AboutKidsHealth.

In hemophilia, the clotting process slows. This does not mean an injured person with hemophilia will bleed more quickly than a person without hemophilia, but that they will bleed for a longer period of time, and symptoms depend on the severity of hemophilia.

Symptoms of hemophilia include:

  • prolonged bleeding after cuts, surgery, bloodwork or dental procedures

  • mouth bleeds

  • easy bruising

  • joint and muscle swelling

Hemophilia mainly affects males; females are usually carriers of the condition. A female will only have hemophilia if she receives the hemophilia gene from both parents, and will experience only very mild bleeding symptoms. However, males only require one X chromosome with the hemophilia gene to inherit the condition.

Without treatment, people with severe hemophilia can develop serious internal bleeding and long-term joint damage from bleeds.

How is hemophilia treated?

Children with severe hemophilia, or those who have severe bleeds often, may need a dose of clotting factor on a regular basis to prevent bleeds from happening. Those with mild hemophilia may only receive a dose of clotting factor when an injury occurs.

Learn more about types of hemophilia, how it is inherited, and various treatment options in the AboutKidsHealth article, “Hemophilia”.

AboutKidsHealth is SickKids' health education website, which offers more than 3,500 articles, illustrations and videos on a range of paediatric health topics. For more information on hemophilia and other health topics, visit