For a blood test, a small sample of your blood is taken. This is sent away to be tested in a laboratory.
You can’t be diagnosed with WM from blood tests alone, but they are often the first marker that there might be a problem and will prompt your doctors to investigate further.
What are they looking for?
There are lots of different types of blood tests, and what you’re tested for will depend on the symptoms you have and the results of previous tests. The most common blood test is called the Full Blood Count.
A Full Blood Count (FBC) measures the levels of red cells, white cells and platelets in your blood. The blood ‘count’ refers to the amount of each type of blood cells. WM can cause low levels in these ‘counts’, which can cause symptoms you may have been experiencing, for example a low red blood count can cause symptoms of anaemia.
Other blood tests that help doctors diagnose and monitor WM are:
• Serum immunoglobulin which measures the level of antibodies in your blood. People with WM have high levels of an antibody called IgM
• Plasma viscosity which measures how viscous (or thick) your blood is. High levels of IgM can cause the blood to become thicker
• Beta-2 microglobulin measures a protein called beta-2 microglobulin, which can let doctors know how severe the disease it. Higher levels of beta-2 can mean a more severe disease.
After diagnosis, blood samples are taken and tested regularly to monitor your symptoms and, alongside these symptoms, can help your doctors understand when you might need treatment.
What happens in a blood test?
There normally isn’t anything you need to do before to prepare for a blood test. If you do need to prepare, your doctor or nurse will let you know. It’s important to let the team know of any medications (prescribed and over-the-counter) you take beforehand.
The doctor, nurse or phlebotomist (a person who is trained to take blood) will clean your skin where the blood will be taken from (usually in the upper arm at the bend of your elbow, where the vein is visible through the skin). They’ll wrap a band tightly about your upper arm to make the vein swell. They’ll insert a needle into your vein to take the blood samples – this might sting a little bit. If you are in pain, tell the person taking your blood.
The blood is collected in tubes – the number depends on what tests have been ordered (usually 2-3). Don’t worry, it might look like a lot, but the samples of blood are only small. Once they’re finished, they’ll remove the band from your arm and take the needle out. They’ll tape a plaster or small dressing over where the needle went in, and you’ll be able to remove this in a few hours.
Some people feel dizzy or nauseous when they have blood tests done. If you know you often feel like this, it’s worth seeing whether someone can come with you to the test, to care for you afterwards. If you come over ill during or after your test, sit down and tell your doctor or nurse who will be able to help.