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  • Writer's pictureSpot Leukaemia

What causes random bruises without injury and is it serious?

From catching your elbow to bumping your head, we all get bruises from time to time. And we can normally explain how they got there. But what causes random bruises to appear without injury? Unexplained bruising, especially in unusual areas, such as the back of the legs or armpits, can be a sign of an underlying medical issue and, although not always serious, it’s worth getting checked out.

Random bruises are a symptom associated with leukaemia, a type of cancer that affects the blood and bone marrow. In this post, we’ll take a closer look at unexplained bruising and its potential link to leukaemia.

Bruising and leukaemia

Leukaemia is a type of cancer affecting the blood and bone marrow. It leads to the over-production of abnormal, cancerous white blood cells. This prevents the body creating normal blood cells, including platelets.

A bruise forms when small blood vessels near the skin break, usually due to an impact. Blood leaks out of the vessels but platelets help the body to clot blood and stop the bleeding - reducing the chances of it leaving a visible mark.

If we don’t have enough platelets, the body isn’t able to stop the bleeding, which can lead to us bruising more easily and more extensively. It also causes us to bleed more, including heavier periods, bleeding gums and nose bleeds.

What does leukaemia bruising look like?

Like normal bruising, leukaemia bruising can happen all over the body. However, unlike normal bruising, leukaemia bruising is also common in unusual places, like your back, hands and armpits.

Also take note of how long the bruising takes to disappear. Regular bruises don’t usually take longer than a month (and normally only a couple of weeks) to disappear. If bruises regularly take longer than that to fully heal, it may be worth speaking to your doctor.

Also take note if the bruises appear alongside any other leukaemia symptoms, such as extreme fatigue and repeated infections.

Other leukaemia symptoms

Along with random bruising, there are other symptoms associated with leukaemia. These include:

  • Unexplained bleeding of the gums: because leukaemia affects platelet production, it also impacts how we bleed. This can result in bleeding gums, nose bleed and very heavy periods

  • Frequent infections: leukaemia weakens the immune system, making us more susceptible to infections, such as colds, flu and ear infections

  • Extreme fatigue: because of how leukaemia decreases the production of red blood cells, it limits the amount of oxygen that reaches our body’s tissues, causing overwhelming fatigue that doesn’t get better with rest, hydration or lifestyle changes

If you’re experiencing bruising alongside other symptoms like frequent infections and extreme fatigue, it’s something worth taking note of and getting checked out with your GP or healthcare practitioner.

What to do if you’re concerned about unexplained bruising

What causes random bruises to appear without injury? There are plenty of things that can cause unexplained bruising. However, if they’re appearing more often and in unusual places, especially if accompanied by other symptoms like frequent infections and extreme fatigue, you should contact your doctor immediately to request a blood test.

Early detection and proper and timely care saves lives when it comes to leukaemia, so it’s vital to address any concerns you’ve got as soon as possible.

Find your local GP.

Find out more about other leukaemia symptoms.


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