Signs of Blood Cancer and How It’s Diagnosed

Medically Reviewed by Melinda Ratini, MS, DO on February 29, 2024
8 min read

Several kinds of cancer attack the cells that make up your blood. Their symptoms usually come on slowly, so you might not even notice them. And some people have no symptoms at all.

But there are a few things to look for with the most common kinds of blood cancer.

Blood cells are made inside your bone marrow, and that’s where leukemia starts. It causes your body to make white blood cells that grow out of control and live longer than they’re supposed to. And unlike normal white blood cells, they don’t help your body fight infection.

There are many different forms of leukemia. Some get worse quickly (acute). You’ll probably feel very sick very suddenly, like you’ve come down with the flu. Other forms can take years to cause symptoms (chronic). Your first clue may be abnormal results on a routine blood test.

Most signs of leukemia happen because the cancer cells keep your healthy blood cells from growing and working normally.

Anemia: This is when your body doesn’t make enough red blood cells, or the ones you have don’t do their jobs well. Signs of it include:

  • Feeling tired and weak
  • Shortness of breath
  • Dizziness
  • Pale skin
  • Chest pain

Poor clotting: Platelets are the cells that make your blood clot. When your body doesn’t make enough of them, small cuts may bleed more than usual, or you might have a bloody nose often. You may also have:

  • Unusual bruising
  • Bleeding gums
  • Tiny red dots on your skin from broken blood vessels
  • Heavy periods
  • Bowel movements that are black or streaked with red.

Other symptoms: Because your white blood cells don’t fight infection well, you’ll get sick more often and take longer to get over it. You may get a lot of fevers and have night sweats.

  • Cancer cells can build up in your lymph nodes, tonsils, liver, and spleen and cause them to swell.
  • You may feel lumps in your neck or armpit, or you may feel full after only eating a small amount.
  • You may lose a lot of weight without trying.
  • The growth of cancer cells in your bone marrow sometimes causes bone pain.

Your lymph system carries infection-fighting white blood cells called lymphocytes throughout your body and helps get rid of waste. Lymphoma causes your body to make lymphocytes that grow out of control and make it harder for you to fight infection.

Swollen lymph nodes are the main sign of lymphoma. You may notice a lump in your neck, armpit, or groin. Lymph nodes farther inside your body may press on your organs and cause coughing, shortness of breath, or pain in your chest, belly, or bones.  Your spleen may get bigger, making you feel full or bloated. The swollen nodes aren’t usually painful, but they may hurt when you drink alcohol.

Some other common signs of lymphoma are:

  • Fever
  • Night sweats
  • Feeling tired
  • Unexplained weight loss
  • Itchy skin

The plasma cell is another type of disease-fighting cell in your bloodstream. Multiple myeloma causes your bone marrow to make plasma cells that grow out of control and keep your body from making enough healthy blood cells. They also release chemicals into your blood that can hurt your organs and tissues.

Some forms get worse faster than others, but symptoms typically don’t show up until you’ve had it for a while.  

Bone pain: The most common sign of multiple myeloma is serious and long-lasting pain, usually in your back or ribs. The cancer cells release a chemical that stops the normal growth and healing process in your bones. They get thin and weak and can break easily.

Damage to the bones in your spine can put pressure on your nerves and cause pain or weakness in your legs, tingling in your arms, and loss of bowel or bladder control.

Hypercalcemia: Multiple myeloma causes high levels of calcium in your blood. That can lead to:

  • Nausea and stomach pain
  • Excessive thirst and urination
  • Constipation
  • Loss of appetite
  • Weakness
  • Confusion

Too much calcium in your blood can also hurt your kidneys. Certain proteins made by the cancer cells can, too. Signs include swollen ankles, shortness of breath, and itchy skin.

Other multiple myeloma symptoms: The proteins the cancer cells release can damage your nerves, which can cause weakness, numbness, and pain in your arms and legs. Multiple myeloma cells also crowd out healthy cells in your blood. That can cause bleeding problems and make you anemic and more likely to get infections.

If your doctor thinks you might have blood cancer, specific  tests can help them find out for sure. You may need to have more than one to know what’s going on.

A nurse or technician will take some blood from a vein in your arm near your elbow. Your medical team can use the sample for:

  • Complete blood count (CBC): This common test measures the white blood cells, red blood cells, and other things that make up your blood. If the test finds too many or too few of some of them, that can be a sign of a problem.
  • Blood smear: If the complete blood count doesn’t give clear results or your doctor thinks your body isn’t making blood cells the way it should, they may recommend this test. It tells whether the blood cells look normal and if you’ve got the right number of them.
  • Blood chemistry: This measures blood sugar, cholesterol, proteins, electrolytes, and other things in your blood. That tells your doctor about your overall health and can flag some problems.
  • White cell differential: This measures the different kinds of white cells in your blood. The results help show how well your body can fight infection. They also can show signs of some types of blood cancers, like leukemia, and tell how advanced they are. This is often done as part of a routine CBC.
  • FISH (fluorescence in situ hybridization): This focuses on blood cancer cells. It tells whether the genetic blueprint that guides their growth is changing. The results will help your doctor give you the right treatment.
  • Flow cytometry: If your blood has too many white cells, this can tell if cancer is the reason for that. The test measures the number of white cells and notes their size, shape, and other traits. It can be done on your blood or your bone marrow.
  • Immunophenotyping: This can tell the difference between the types of cancer cells. That can help your doctor figure out the best treatment for you.
  • Karyotype test: This looks for changes in the size, shape, number, or arrangement of chromosomes in blood or bone marrow cells. It can help your doctor plan your treatment.
  • Polymerase chain reaction: This can spot markers of cancer. It can pick up on things that other tests miss and tell your doctor how well your treatment is working.

Your bones are hard on the outside, but they’re more like sponge in the middle. That part is called the marrow, and it’s where your red blood cells and white blood cells are made.

Your doctor may need to find out if a disease is attacking your bone marrow. Some illnesses show up there before they do in your blood.

Your doctor probably will take a small amount of marrow from your hip. First, your medical team will numb the area. They also might give you medicine to make you drowsy.

Then your doctor probably will do two things:

  • Bone marrow aspiration: They'll use a hollow needle to take out a little of the fluid inside your bone marrow.
  • Bone marrow biopsy: They'll use a slightly larger needle to take out a piece of the solid part of the marrow.

It usually takes about 30 minutes. You might have it done in a hospital, clinic, or your doctor’s office.

The samples will go to a lab, where technicians will figure out whether your bone marrow is making enough healthy blood cells. They’ll also look for unusual cells. Those results can help your doctor:

  • Confirm or rule out certain illnesses
  • Figure out how advanced a disease is
  • See whether treatment is working

Blood cancer may affect part of your immune system called your lymphatic system. It runs throughout your body, and it includes your tonsils and spleen, along with lymph nodes that are about the size of beans. Your body has hundreds of them, and they have white blood cells to help fight infections and illnesses.

Your medical team may want to take out part or all of a node to look for cancer. Doctors call that a lymph node biopsy.

The surgical team will take you into an operating room in either a hospital or an outpatient center. They’ll make the area numb around where they’re going to take out the node, but they probably won’t put you to sleep.

Your doctor will make a small cut and take out the node, then close the spot with stitches. It shouldn’t leave a scar.

When your medical team studies the lymph node, they can look for cancer tumors, masses that aren’t cancerous, or infections. That can tell them whether you have lymphoma, a kind of cancer that attacks the lymphatic system.

These painless tests let your doctor see inside you. They may show tumors or other conditions.

  • Chest X-rays: These can help your doctor spot a tumor, an infection, or a large lymph node.
  • CT (computed tomography) scan: Your doctor will use a machine that takes X-rays from different angles. They’ll put those images together to make a more complete picture. That can show large lymph nodes and other organ abnormalities, or help your doctor see if cancer has returned after treatment. To get the test, you lie on an exam table, and the scanner rotates around you. It usually takes 10-30 minutes.
  • MRI (magnetic resonance imaging) scan: This uses powerful magnetic and radio waves to make detailed pictures of your organs, blood vessels, or bones. It can help your doctor spot tumors or look for changes in your bones that signal a type of blood cancer called myeloma. You’ll lie on a table that slides you inside a machine that’s like a little tunnel. If going into a tight space makes you anxious, the medical team may give you medicine to relax you. The exam takes 15-45 minutes.
  • PET (positron emission tomography) scan: This uses a radioactive form of sugar to show your metabolism at work. It can tell your doctor if you have lymphoma or other cancers. When you get the test, the technician will give you a shot that has the sugar in it. You’ll lie down on an exam table, and it will slide you inside the scanner. If small spaces stress you out, the team may give you medicine to relax you. It takes around 45 minutes.

This test looks at a sample of the fluid around your brain and spinal cord. It can tell your doctor if the fluid has any blood cancer cells. You may hear this test called a lumbar puncture.

You’ll lie on your side, and your medical team will make part of your back numb. Then your doctor will use a needle to take out a little fluid from between the bones in your spine. They'll put a bandage on the spot in your back, and the fluid sample will go to the lab.

This measures proteins, blood cells, and other substances in your urine. Chemicals in your blood often end up in your urine after your kidneys filter them out.