A blood test is a sample of blood taken so that it can be tested in a laboratory. Blood contains blood cells, chemicals and proteins. By examining your blood, doctors can find out more about your general health. The doctors can also find out more about how the lymphoma and treatment are affecting the body.
Why is a blood test needed?
Blood tests may be done as part of diagnosing and staging lymphoma. They help the medical team monitor how the body is responding to treatment, as well as giving a general picture of your overall health. It is likely that a patient will have many blood tests throughout treatment and follow up care. Once you are in follow-up care or if you are in watch and wait, you will have less frequent blood tests.
Blood tests can be done for many different reasons including:
- Check general health
- Check the functioning of kidneys and liver
- Help with diagnosing some types of lymphoma
- Monitor the treatment
- Check the recovery from one treatment cycle before starting the next one
What happens before the test?
In most cases there is nothing to be done to prepare for a blood test. For some blood tests fasting may be required (go without food or drink) prior to the test. Some medications may need to stop or some foods should be avoided. If you need to do anything prior to the test this will be explained to you by your doctor or nurse. If you are unsure about any requirements it is important you check with your medical team.
What happens during the test?
If you are not in hospital your doctor or nurse will tell you where you need to go to have your blood test. This may be at your local hospital, a pathology department, a community nurse or your GP. The blood sample will be taken using a small needle. This is inserted into a vein most often in your arm. It takes only a few seconds to obtain the sample, then the small needle is withdrawn. If you have a central venous access device the nurses may be able to use this to obtain the blood sample.
What happens after the test?
If you are an outpatient, you can usually go straight home after the test unless you need to stay at the hospital for an appointment or treatment. Some blood tests results are available within minutes and some take a couple of weeks to come back. Check with your doctors about how you will get the results and how long it will take. Waiting for results can be difficult, speak with your team if you feel anxious about your test results.
What do my results mean?
Your medical team should explain your blood test results to you. You can get a copy of your blood test results but you may find them difficult to interpret. It is a good idea to sit with your doctor or nurse and ask them to explain the results.
Sometimes on the report you will notice that your blood test might be “out of reference range” or different to the listed “normal range”. Do not be worried as this is common for many people. Most people’s blood results are within the reference range.
However around 1 in 20 healthy people have results outside the reference or normal range. Many things can cause this, for example age, sex or ethnicity.
The doctors will look at your blood results and decide if there is anything to be concerned about as they know your individual circumstances.
Are there any risks?
A blood test is generally a very safe procedure. You may experience a small sting when the needle is inserted. You may have a small bruise and get a slight ache at the site after the blood test is complete. This is usually very mild and gets better quickly. There is a very small risk of developing an infection. Talk to your medical team if you experience any worrying symptoms such as pain or swelling. Some people may feel faint or lightheaded when having a blood test. It is important to tell the person taking your blood if this happens or if this has happened to you in the past.
Blood tests for lymphoma patients
There are many different routine blood tests used for people with lymphoma. Below are some of the most common.
- Full Blood Count: this is one of the most common blood tests performed. This test tells the doctors about the numbers, types, shape and sizes of cells in the blood. The different cells that are looked at in this test are;
- Red Blood Cells (RBCs) these cells carry oxygen around your body
- White Blood Cells (WBCs) fight infection. There are different types of WBCs (lymphocytes, neutrophils and others). Each cell has a specific role in fighting infection.
- Platelets help your blood to clot, preventing bruising and bleeding
- Liver function tests (LFTs) are used to see how well your liver is working.
- Kidney function tests such as urea, electrolytes and creatinine (U&Es, EUC) are tests that are used to assess kidney (renal) function
- Lactate dehydrogenase (LDH) this test can help to identify tissue cell damage in the body, and to monitor its progress
- C-Reactive Protein (CRP) is used to identify the presence of inflammation, to determine its severity, and to monitor response to treatment
- Erythrocyte sedimentation rate (ESR) can detect and monitor signs of inflammation in the body
- Plasma Viscosity (PV) shows the thickness of your blood. This is an important test to have if you are diagnosed with Waldenstrom’s macroglobulinemia
- Serum protein electrophoresis (SPEP) Is an important test that measures abnormal proteins in your blood if you are diagnosed with Waldenstrom’s macroglobulinemia
- International normalised ratio (INR) and PT these tests measures how long it takes for your blood to begin to form clots. You may have this done prior to surgical procedures, lumbar punctures or bone marrow biopsies.
- Screening for exposure to viruses which could be related to the lymphoma, this may be done as part of your diagnosis. Some viruses that you may be screened for include;
- Human immunodeficiency virus (HIV)
- Hepatitis B and C
- Cytomegalovirus (CMV)
- Epstein Barr virus (EBV)
- Blood group and crossmatch if a blood transfusion is needed
The medical team might suggest other blood tests depending on the individual circumstances.