Lymphoma is a blood cancer in which white blood cells called lymphocytes develop abnormally and crowd out healthy cells. Your doctor will need to perform a lymph node or bone marrow biopsy to diagnose lymphoma, but blood tests can still offer valuable information before, during, and after treatment.

Getting blood drawn and waiting for results can be stressful. Here, we explain what blood tests are used for in lymphoma and how to understand your blood test results.

How Are Lymphoma Blood Tests Used?

Although blood testing can’t diagnose Hodgkin or non-Hodgkin lymphoma (NHL), it can help your health care team understand how lymphoma and its treatments are affecting you. If blood tests indicate that there might be a problem, your doctor may next do a physical exam or order imaging tests such as an X-ray, a magnetic resonance imaging (MRI) scan, or a PET/CT scan.

Several types of blood tests are available for people with lymphoma. Each can reveal details about different aspects of your general health.

Types of Blood Tests for Lymphoma

These are some of the most common blood tests that your doctor may order to help monitor lymphoma and make decisions about your treatment options:

• Complete blood count
• Tumor marker blood tests
• Lactate dehydrogenase tests
• Plasma viscosity tests
• Antibody testing
• Urea and electrolyte testing

Complete Blood Count

The most common type of blood test for lymphoma is a complete blood count (CBC), also known as a full blood count. This test uses a blood sample to measure the number of different types of cells in your blood.

A CBC will measure how much of each type of blood cell you have in your blood. There are three main types of cells: red blood cells, white blood cells, and platelets. Here’s a breakdown of what’s tested for in a CBC and what its results can tell your doctors.

Red Blood Cells

Also called erythrocytes, red blood cells carry oxygen from the lungs all through the body. In addition to measuring your red blood cell levels, a CBC will usually measure your hematocrit and hemoglobin levels. Hematocrit levels reveal the percentage of your blood that’s made up of red blood cells. By measuring hematocrit and hemoglobin, a protein in red blood cells, your doctor can better see how well these blood cells are doing their job.

A CBC can also tell doctors if you are anemic. This means that you don’t have enough red blood cells in your bloodstream. Because these cells transport oxygen throughout your body, low levels can make you extremely tired. This is one key sign of NHL.

White Blood Cells

The immune system’s first line of defense involves white blood cells, which attack bacteria and viruses that enter the body.

People who have lymphoma may also have a low white blood cell count, which may indicate a vulnerable immune system.

Platelets

Known as thrombocytes, platelets are small cell fragments that gather at sites of injury and help the blood clot.

Your doctors may also look for low platelet levels during a CBC. If your platelet count is too low, your blood may have difficulty clotting properly if you’re injured. Low platelets often suggest that the bone marrow is affected by lymphoma.

Tumor Marker Blood Tests

Some subtypes of NHL cause abnormalities in the levels of certain substances (mostly proteins) in your bloodstream. These cancer marker substances can be measured with tests like cytochemistry and immunophenotyping done by flow cytometry.

Some tumor markers are tied specifically to one type of cancer. Others may be linked to several types, and a few may be related to other conditions. Finding these markers can be useful for diagnosing both B-cell lymphoma and T-cell lymphoma, monitoring how severe your NHL is, or determining how well your lymphoma treatment is working.

Lactate Dehydrogenase Tests

Another common blood test for those diagnosed with NHL is a lactate dehydrogenase (LDH) test. This protein shows that cells are being destroyed or are dying. People diagnosed with NHL may have higher levels of LDH. Although there can be many reasons you might have more LDH than normal in your bloodstream, one explanation is NHL.

Plasma Viscosity Tests

This test is designed to determine how viscous (thick) your blood is. It can help your doctors monitor your lymphoma, particularly if you have been diagnosed with a type of NHL called lymphoplasmacytic lymphoma (also called Waldenström’s macroglobulinemia). In this condition, cancer cells produce abnormal immune proteins called antibodies that make the blood viscous. The results of a blood viscosity test can show whether treatments for NHL are working.

Antibody Testing

If you have certain types of NHL, you may also need to undergo antibody testing. Your oncology team may choose to run a serum immunoglobulin test or a serum protein electrophoresis test. These results show doctors which antibodies are in your bloodstream and at what levels. These results can help track how lymphoma is progressing or show how well a treatment is working.

Urea and Electrolyte Testing

When doctors test your blood for urea and electrolytes, they are looking at how well your kidneys are working. Your kidneys are designed to break down these substances and remove them from the body through your urine. If there are high levels of urea or electrolytes in your bloodstream, your kidneys may need extra support. Because NHL can affect the whole body, these tests can show if the cancer is affecting kidney function.

Preparing for Your Blood Test

Most of the time, you won’t need to prepare for your blood test. If you do need to do anything ahead of time, you should receive specific instructions from your doctor or the lab. You may need to fast (not eat or drink) or adjust your medication schedule — or not take medications at all — for a certain amount of time before the test.

Getting Your Blood Test Results

Most blood tests don’t take too long. Sometimes, you can even get your results within a few minutes. However, you should always discuss your blood tests with your doctor, who’s trained to interpret your results based on the other medical information available and your medical history. They will have the full picture and can help you understand what the results mean for your overall health and treatment plan.

Talk With Others Who Understand

On MyLymphomaTeam, the social network for people with lymphoma and their loved ones, more than 19,000 members come together to ask questions, give advice, and share their stories with others who understand life with lymphoma.

Are you feeling anxious about getting your lymphoma blood test results? Have you discussed the results with your doctor? Share your experience in the comments below, or start a conversation by posting on your Activities page.