Bruising or bleeding is one of the most common symptoms associated with a blood cancer diagnosis. According to our 2018 patient survey, “Living with Leukaemia”, frequent bruising and bleeding precedes a diagnosis of leukaemia in 24% of patients.
Bruising is defined as bleeding that occurs underneath the skin, causing black, blue or purple marks to visibly appear on the skin’s surface. Most of the time there is no reason to worry about bruising as it is the body’s natural response to injury. However, because bruises from leukaemia are very similar in appearance to ordinary bruises, they can be too easily dismissed as harmless.
The manner in which you get bruises and how long they last can be a tell-tale sign of leukaemia and may be a reason for you to book an appointment with you doctor. Spotting the difference between harmless and harmful bruising may be key in diagnosing leukaemia early.
Spotting the difference
Although bruises from leukaemia are very similar to ordinary bruises, there are a few things you can look out for to help spot the difference:
- They occur in unusual places – In cases of leukaemia, quite often bruises will appear in places that you wouldn’t normally expect, especially; the back, legs, and hands.
For children, bruises may start to appear on the face, buttocks, ears, chest, and head.
“I noticed some unexplained bruises on my right hand and lower limbs.”
- There are lots of them – It is not unusual to have a few bruises on your body at once, especially if you are an active person. However, multiple bruises without explanation is a reason for concern.
“I counted 40 bruises on my body; I just thought I bruised easily.”
- You can’t explain why they are there – The bruises may appear without any clear reason. In other words, bruising without damage to that part of the body. They might also develop after very slight knocks that wouldn’t normally cause a bruise.
“I was bruising where I didn’t remember hitting myself.”
- They take longer than usual to disappear – Bruises may last for longer than you would expect or might continue to grow in size.
A normal bruise tends to heal after around two to four weeks. Therefore, if a bruise lasts for more than four weeks, we recommend getting it checked by your GP.
“The bruises tended to sort of keep on bleeding underneath the skin.
- You have been experiencing excess bleeding – Since bruising is a form of bleeding (it’s just underneath the skin), unusual bleeding from other areas of the body can also be a sign of leukaemia (e.g. heavy periods, frequent nosebleeds or bleeding gums).
“I was almost constantly bleeding from the mouth and the bruises were all over my body.”
So what causes bruising and bleeding in leukaemia?
As with most of the symptoms of leukaemia, bruising is caused by a deficiency of healthy blood cells within the bone marrow. The bone marrow is a spongy tissue found in the centre of some of your bones. It contains stem cells which develop into all the various blood cells. In leukaemia, the bone marrow starts to produce an excess amount of abnormal or un-developed (cancerous) white blood cells. These cancerous cells eventually accumulate and “crowd out” the normal blood cells in the bone marrow, preventing them from being produced.
One blood cell type that can be crowded out by the rapidly dividing leukaemic blood cells are the platelets. Platelets are small cell fragments that flow through the blood and are responsible for causing blood to clot after you injure yourself. Therefore, if you have leukaemia, you are more likely to bruise because your body is unable to produce enough platelets to plug up your bleeding blood vessels. Healthy adults will have between 150,000 and 450,000 platelets in every microlitre of their blood; any less than this will cause bleeding. The scientific name for this is “thrombocytopenia”.
Small red spots (petechiae)
As well as medium-to-large bruises, you might notice “rashes” appearing on your skin. Small, pinhead-sized red spots on the skin (called “petechiae”) may be a sign of leukaemia. These small red spots are actually very small bruises that cluster so that they look like a rash.
“I noticed an unusual rash on his torso whilst giving him a bath.”
They can be purple, red or brown in colour and usually they occur on the arms, legs and stomach, but they can also be found on the inside of your mouth and around your eyes. The spots are caused by damage to very small blood vessels in the skin (called capillaries). Due to a lack of platelets, people with leukaemia cannot properly seal these damaged blood vessels so that small amounts of blood leak into the skin. Normally, petechiae is harmless and is caused by physical strains to the body. For example, hard coughing, vomiting and crying can cause petechiae to occur in the face. However, it may be that someone with leukaemia may start to notice this becoming a problem when it wasn’t before.
Finally, leukaemia can change the appearance of the skin in a completely different way. As well as leaving dark coloured bruises and rashes over the body, you may find that your skin pales elsewhere. People with leukaemia sometimes appear paler than normal because of anaemia. Because red blood cells can also be crowded out in the bone marrow, skin that is paler than a person’s usual complexion may occur due to a reduced amount of functioning red blood cells supplying the skin.
When should I be concerned?
If you start noticing bruising or rashes on your body, there is no need for immediate concern. In most cases, the cause will not be serious. However, it is for this exact reason that leukaemia can be hard to spot, as the signs and symptoms are so easily confused for more common illnesses. If your bruises occur frequently or are not disappearing, you should contact your doctor immediately.
Knowing what other symptoms are typical of leukaemia is crucial for helping you to make the decision to visit your GP sooner for a blood test. Connect the dots between the symptoms of leukaemia and spot leukaemia sooner.
For information on the other symptoms of leukaemia, click here.