Medically Reviewed by Jabeen Begum, MD on February 26, 2024
15 min read

Leukemia is a type of blood cancer caused by a rise in the number of white blood cells in your body.

Those white blood cells crowd out the red blood cells and platelets that your body needs to be healthy. The extra white blood cells don’t work right.

Leukemia vs. lymphoma

Lymphoma is a different kind of blood cancer that also affects white blood cells. Because they have some things in common, doctors think of leukemia and lymphoma as “cousins.”

With both leukemia and lymphoma, certain blood cells don’t develop normally. But with lymphoma, these abnormal cells clump together and form tumors in the lymphatic system. The lymphatic system includes your tonsils, spleen, lymph nodes, and lymph vessels, and it helps flush infections out of your body. With leukemia, the abnormal cells stay in your blood as it flows through your body.

Leukemia and lymphoma both affect your body’s ability to fight off invaders. But treatments for leukemia and lymphoma are different because they impact different parts of your body.

No one knows exactly what causes leukemia. People who have this disease have certain unusual chromosomes, but the chromosomes don’t cause leukemia.

How does leukemia happen?

Blood has three types of cells: white blood cells that fight infection, red blood cells that carry oxygen, and platelets that help blood clot.

Every day, your bone marrow makes billions of new blood cells, and most of them are red cells. When you have leukemia, your body makes more white cells than it needs.

These leukemia cells can’t fight infection the way normal white blood cells do. And because there are so many of them, they start to affect the way your organs work. Over time, you may not have enough red blood cells to supply oxygen, enough platelets to clot your blood, or enough normal white blood cells to fight infection.

Leukemia classifications

Leukemia is grouped based on how fast it develops and gets worse and which type of blood cell is involved.

Based on how fast it develops, leukemia is divided into:

  • Acute leukemia, which happens when most of the abnormal blood cells don’t mature and can’t carry out normal functions. It can get bad very fast.
  • Chronic leukemia, which happens when there are some immature cells, but others are normal and can work the way they should. It gets worse more slowly than acute forms do.

Based on the type of cell involved, leukemiais divided into:

  • Lymphocytic (or lymphoblastic) leukemia, which involves the bone marrow cells that become lymphocytes, a kind of white blood cell.
  • Myelogenous (or myeloid) leukemia, which involves the marrow cells that create red blood cells, platelets, and other kinds of white blood cells.

The four main types of leukemia are:

Here is a list of symptoms that you might have if you have leukemia:

  • Weakness, fatigue, or getting tired easily
  • Unusual bruising
  • Bleeding easily
  • Skin changes, including small red spots (called petechiae) or patches that are blue, purple, or darker than the rest of your skin
  • Paler skin than usual
  • Fever or chills
  • Infections that are severe or keep coming back; getting sick more often
  • Pain in your bones or joints
  • Headaches
  • Weight loss
  • Night sweats
  • Shortness of breath
  • Swollen lymph nodes, liver, spleen, or tonsils

What is the first sign of leukemia?

The first signs of leukemia will vary by what kind of leukemia you have. With some forms of leukemia, you might not have any symptoms at first. Signs of leukemia in adults are related to the cancer cells in your blood. These cells crowd out other blood cells and stop them from doing their jobs correctly. Here’s how leukemia might affect you at first:

  • Trouble fighting off infection. Your white blood cells help your body fight germs. With leukemia, immature cells that would usually become white blood cells turn into cancer cells instead. This is why you might get sick more easily, have fevers, or take longer than usual to get better if you do get sick.
  • Bruising and bleeding. Cancer cells push out the cells that make your blood clot, so you are more likely to bleed or bruise, even from small scrapes or taps that usually wouldn’t leave a mark. You might get unexplained bruises, nosebleeds, bleeding gums, and heavier periods.
  • Swollen lymph nodes, for example in your neck, armpits, thighs, groin area, or belly. You might also have swelling in your liver or lymphatic system organs, such as your spleen or tonsils.
  • Not feeling well. You might have shortness of breath, fatigue, headaches, night sweats, weight loss, a feeling of fullness or pain under your ribs on your left, or pain in your bones or joints.

Leukemia bruises

Bruises happen when blood pools under your skin. They can be purple, red, blue, or darker than the skin around them, and they might hurt or ache. If you have leukemia, you are more likely to get bruises, because you have fewer platelets to “patch” leaks from small injuries.

A survey found that about 1 in 4 people with leukemia noticed they were getting more bruises than usual before they found out they had cancer. You might have bruises in unusual places, such as your hands, face, ears, back, legs, or chest, even if you don’t remember hurting yourself or bumping into anything. Bruises might be more painful or severe, and they might take longer than usual to heal or have small red spots around them, called petechiae. You might also get swollen bruises called hematomas that feel like a lump or knot under your skin.

Your doctor might treat your bruises by giving you medications or platelets to replace the ones that cancer cells crowd out. Some medicines to treat leukemia might also make you bruise more easily.

You should see your doctor if you or your child have bruises often, or if your bruises take a long time to get better.

You can’t prevent leukemia, and scientists don’t know how to predict who will get it. But certain things might raise your risk of getting it. These include:

  • Smoking. People who smoke or are around secondhand smoke are more likely to get a kind of leukemia called AML.
  • Being around certain chemicals at work. People who work around chemicals such as benzene and formaldehyde have a higher risk of getting leukemia. People might also be exposed to harmful chemicals in the environment.
  • Other cancer treatments. Sometimes, people who have had treatments such as radiation therapy or chemotherapy for other kinds of cancer might end up with leukemia.
  • Some genetic conditions. People born with Down syndrome, Klinefelter syndrome, neurofibromatosis, or other conditions are more likely to get leukemia. If you have a condition that affects your leukemia risk, ask your doctor if there are any special tests or screenings you might need.
  • Radiation. People who have been exposed to a lot of radiation are at higher risk of leukemia.
  • Race. Your race and ethnicity can impact your risk of getting leukemia. For example, children who are Latino/a, Hispanic, or of Spanish descent are more likely than non-Latino kids to get leukemia. Research shows that people of Asian descent have a higher risk of getting acute myeloid leukemia (AML) but a lower risk of other leukemia types. People who are Black have a lower chance of getting most types of leukemia than people of other races.
  • Gender. People who are assigned male at birth (AMAB) are a little bit more likely to get leukemia than people who were assigned a different sex.
  • Family history. If other people in your family have had leukemia, you might be more likely to get it.
  • Age. Leukemia is more common in children and adults older than 55.

Your doctor will need to check for signs of leukemia in your blood or bone marrow. They might do tests including:

  • Physical exam. Your doctor will check you for symptoms of leukemia, such as bleeding gums, bruises, being more pale than usual, fever, or swelling in your lymph nodes, spleen, or liver. They will also ask you questions about how you’ve been feeling and any other symptoms you’ve had.
  • Complete blood count (CBC). This test looks at the number and maturity of different types of cells in your blood. With leukemia, you’ll probably have more white blood cells than normal, and you might have fewer red blood cells and platelets because cancer cells crowd them out. Primary care providers sometimes take CBCs as part of your annual physical. 
  • Other blood tests. Tests such as flow cytometry and peripheral blood smears check your blood for cancer cells and other leukemia signs such as immature cells. These tests can help figure out what kind of leukemia you have. Your doctor might also do blood tests to check on your liver and kidneys and see how well your blood clots.
  • Bone marrow biopsy. This test checks for leukemia cells and other changes in your bone marrow, the soft spongy tissue inside your bones where your blood cells are made. First, your doctor will give you some numbing medication. Then, they’ll use a thin needle to take a small sample of bone marrow from inside your hip bone. Looking at the sample in the lab can show how many cells are immature and the details of how the cells are changing. This gives you information about how severe your cancer is and which treatment options to try. 
  • Spinal tap. This test is also called a lumbar puncture, and it checks whether leukemia has spread to your nervous system. To do a spinal tap, your doctor will make your skin numb. Then, they’ll take a small sample of fluid from the space between two of the bones in your lower back. The lab will look for cancer cells in the sample.
  • Imaging tests. Tests like CT scans, MRIs, and X-rays that take pictures of your body can help your doctor see how leukemia is affecting you.

There are many different options for treating leukemia. You’ll probably see a doctor and care team focused on taking care of people who have blood cancers, called hematology-oncology. Your team will get all the information they can about what kind of leukemia you have, how fast it’s growing, how much it’s spread, and your overall health. Then, they’ll make a care plan designed especially for you and your unique situation. Here are some treatments you might have:

  • Chemotherapy. Chemotherapy uses very strong medications to kill cancer cells or stop them from growing as fast. Because the medicine is strong enough to kill cancer cells, it can have side effects. Talk to your care team about what side effects to expect, how to prepare for them, and any suggestions for managing them.

    Chemotherapy medications come as pills, shots, creams, and IVs. You might need to visit a doctor’s office or chemotherapy clinic to get IVs or other kinds of chemotherapy. Your doctor will explain the schedule of how often you’ll need chemotherapy treatments.

  • Radiation therapy. This treatment uses X-ray radiation to target cancer cells. Your doctor or technician will use a special machine to point a beam of energy at specific spots. You might get radiation therapy all over or in only one part of your body where there are a lot of cancer cells.

    People often get radiation therapy before they have a stem cell transplant. Radiation also affects other cells in your body, which means it can have side effects.

  • Biologic therapy (also called immunotherapy). Because cancer cells are mutated (changed) versions of your own cells, they are good at getting around your body’s usual defenses against invaders. Biologic therapy is a newer kind of treatment that helps your immune system get better at finding and killing cancer cells. It can boost your body’s natural defenses against leukemia.

    There are different kinds of biologic therapy. Two biologic therapies that are used for leukemia are monoclonal antibody therapy and chimeric antigen receptor (CAR) T-cell therapy. Monoclonal antibody therapy is a way of giving you extra antibodies (“attack cells”) to go after cancer cells. Sometimes, these antibodies are programmed to recognize and target specific parts of the cancer cells. CAR T-cell therapy works by making T-cells (a kind of white blood cells) better at catching cancer cells.

    You get biologic therapy through an IV. Your doctor will let you know what kind of biologic therapy is best for you, and how often you’ll need to get it.

  • Targeted therapy. This newer approach uses medications that get in the way of cancer cells. Targeted therapies can attack specific genes or proteins that cancer cells need to grow, stop the signals they use to divide and spread, cut off their nutrient supply, or kill them directly.

    Because targeted therapy goes right after cancer cells and leaves other cells alone, it often has fewer side effects than other kinds of treatment.

  • Stem cell transplant (also called a bone marrow transplant or hematopoietic cell transplant). A stem cell transplant can replace the leukemia cells in your bone marrow with new, healthy cells. If the transplant works, your bone marrow will copy the healthy blood cells without making more cancer cells.

    A stem cell transplant can use cells from a donor (a person who agrees to give blood or bone marrow). Donors can be family members or people you don’t know who have similar genes. Some transplants use blood from babies’ umbilical cords that their parents chose to donate to a cord blood bank. Doctors can sometimes also take healthy cells from your own body. If this happens, you’ll get shots first that help you grow extra cells.

    Before a stem cell transplant, you’ll get high doses of chemotherapy or radiation to kill off cancer cells and get your body ready to accept the transplant. Then, you’ll get the new cells through an IV or a tube (called a central line). You’ll be in the hospital for a while. They will take steps to help you avoid getting infections while your body heals.

    There are important risks to think about with a stem cell transplant. But for some people, it can stop their leukemia. Your doctor can explain how well it might work for you and help you weigh the risks and benefits.

  • Surgery. Leukemia is different from other kinds of cancers because it lives in your blood; you don’t grow tumors. For this reason, surgery isn’t usually used to treat leukemia directly. But surgery can sometimes help with its impacts on your body. For example, your doctor can remove your spleen if it’s filled with cancer cells and pressing on nearby organs. This procedure is called a splenectomy, and it might help you be more comfortable.

You might have a combination of treatments. Your treatment plan might change based on how well it works and what side effects you have. Ask your doctor or nurse if you have any questions about your personal treatment plan.

If you have an acute kind of leukemia, such as AML or ALL, you’re more likely to need to stay in the hospital for treatment, at least initially. People who have chronic forms of leukemia such as CLL or CML might not need as much monitoring.

As treatment for leukemia and other cancers has gotten better, many people are able to live long lives despite leukemia. How long a person can live with leukemia will depend on what type of leukemia they have, whether it’s acute (fast-growing) or chronic (slower-moving), how old they are, their access to treatment, and if they have other health problems.

One way that scientists think about cancer is by looking at 5-year survival rates. This is the number of people out of 100 who are still alive 5 years after they find out they have cancer. The 5-year survival rate varies for the different kinds of leukemia:

  • With acute lymphocytic leukemia (ALL), over 70 out of 100 people and 92 out of 100 kids are still alive after 5 years.
  • With acute myelogenous leukemia (AML), 30 out of 100 people and 69 out of 100 kids are still alive after 5 years.
  • With chronic lymphocytic leukemia (CLL), almost 88 out of 100 people are still alive 5 years later.
  • With chronic myelogenous leukemia (CML), over 70 out of 100 people are still alive 5 years later.

It’s hard to figure out the 5-year survival rate for children with CLL and CML because it’s so rare for them to get these types of chronic leukemia.

It’s important to remember that people with leukemia are living longer than ever before. Scientists keep working on new treatments for leukemia.

Living with leukemia

Finding out that you have leukemia can be scary, stressful, and overwhelming. It is normal to feel a wide range of feelings. Many people who live with cancer say they had to adjust to a “new normal” after being diagnosed. These are some tips for dealing with leukemia throughout the process.

  • Emotional support. Talk with your friends, family, religious community, neighbors, and other people you love and trust. You might also want to talk to a counselor or other mental health professional. Ask your doctor, nurse, or other care team members to give you referrals. Some counselors focus on helping people who are impacted by cancer.
  • Get practical help. Ask your loved ones to help you with errands, rides, cooking, cleaning, taking care of kids and pets, and other tasks that you might not have as much energy for. Helping you out with these jobs can be a way for your loved ones to deal with your diagnosis. You can keep a running list of things you might need help with and let people who care about you choose a task to help with.
  • Nutrition and food. Your body might need extra nutrients during cancer treatment. Try to eat nourishing, healthy meals and snacks, and your favorite food. Your care team might have suggestions for foods that are easy to make and eat during treatment and other ways of getting the nutrition you need.
  • Other forms of self-care. Talk to your care team about how to stay as active as possible. Take naps if you need them, and try to get enough sleep. Be gentle with yourself.
  • Connect with other people living with cancer. Many people find support groups helpful. Support groups can be in-person or online, and they give you a chance to share your feelings with people who get it. There are support groups for people who are getting specific treatments such as bone marrow transplants or chemotherapy, people at different points in the cancer experience, people of color, LGBTQIA+ people, parents/caregivers or partners of people who have cancer, and many others, as well as cancer support groups that are open to everyone. Ask your care team to help connect you to other people who have similar experiences.
  • Ask questions and learn as much as you can. It’s important to understand what’s happening, your options, and your treatment plan. Your health care team can give you information about what to expect and suggest resources for learning more. Ask them to explain everything, and let them know if you have questions.

Leukemia is a common form of cancer that affects your blood cells. There are many different treatments for leukemia, and your care team will develop a personal treatment plan that takes the specifics of your situation into account. Finding out you have cancer can be scary or overwhelming, so make sure you have as much support as possible. Ask your doctor to explain your options and let them know if you have any questions.

How curable is leukemia?

Like with other kinds of cancers, doctors think it’s hard to completely cure leukemia. But it is possible to have what’s called long-term remission. Remission means that you don’t have any signs of cancer and doctors don’t see any leukemia cells in your blood or bone marrow. 

People can stay in remission for years and years, and their leukemia might never come back. If your leukemia is in remission, your doctor will probably keep testing you every so often, to make sure it doesn’t come back.

How long can leukemia go undiagnosed?

It depends on what kind of leukemia you have and whether it’s chronic or acute. Chronic forms of leukemia such as CLL and CML sometimes don’t have any symptoms at first. People might not find out they have it for years.

With acute forms of leukemia, people are more likely to have symptoms because the cancer cells grow more quickly and start to crowd out regular cells faster. How fast you find out you have leukemia is also affected by how easy it is for you to see a doctor, what symptoms you have, and how they are affecting you.

What is the age of onset for leukemia?

People of any age can get leukemia. But it’s more common in children and people over age 55. Chronic leukemia is very rare in children, and pretty rare for people under 55.