What Is Leukemia? Symptoms, Causes, Diagnosis, and Treatment

Leukemia is a type of cancer that affects the blood cells and bone marrow, a soft spongy tissue inside the bones where blood cells are made. Your blood contains three key types of cells that are made in your bone marrow:

  • White Blood Cells These cells help your body fight infection and other diseases. Some types of white blood cells include lymphoid cells and myeloid cells. (1,2)
  • Red Blood Cells These cells carry oxygen from the lungs to the rest of your body. They usually live for about 120 days before dying. (2)
  • Platelets Platelets are small cell fragments that help your blood clot. (2)

When you have leukemia, your bone marrow makes abnormal cells that can’t accomplish what normal cells can. As the disease progresses, more and more abnormal cells crowd out normal cells, and can even inhibit their production. How fast this happens depends on which type of leukemia you have. (3,4)

Common Questions & Answers

What are the first signs of leukemia?
Early signs of leukemia include fatigue, paleness, easy bruising or bleeding, and a vulnerability to infections.
Can you survive leukemia?
Yes, but there are many different types of leukemia. Some are very slow-growing, and you can live for years or even decades if properly treated. Others are more aggressive, are more imminently life-threatening, and require specialized treatment. Age, stage at diagnosis, and the body’s response to treatment also play a role in survival.
How does leukemia start?
Leukemia starts in the bone marrow, a spongy tissue within bones where blood cells are made. When a leukemia cell forms, it doesn’t perform its role as a regular blood cell, but multiplies at a rapid pace and crowds out normal cells, leaving the body to function without an adequate number of healthy red blood cells, white blood cells, and platelets.
What do leukemia bruises look like?
Because people with leukemia do not have an adequate number of platelets, which help form blood clots, they are prone to bruising. The bruises may look like little red dots, bruises, or large red or purple areas.
What is the difference between acute and chronic leukemias?
Acute leukemias have the potential to be cured with treatments. Chronic leukemias are usually not curable, but their symptoms can be controlled and the disease managed, often for many years, with appropriate treatment.

Classifications of Leukemia

Leukemia is classified by how quickly it grows and the type of blood cell it affects.

Acute vs. Chronic

There are two main categories of leukemia:

  • Acute Leukemia With acute leukemia, the abnormal blood cells that form are immature. This type of cancer typically grows and worsens quickly. It usually requires aggressive treatment.
  • Chronic Leukemia Chronic leukemia worsens gradually over time. It involves more mature blood cells that grow slowly. Some people with chronic leukemia don’t have symptoms for years, and some never require treatment. (4)

Lymphocytic vs. Myelogenous Leukemia

Leukemia is further classified by the type of white blood cell that gives rise to the cancerous cells. Here, too, there are two main categories:

  • Lymphocytic Leukemia Lymphocytic leukemia affects the lymphoid cells (lymphocytes), which are a type of white blood cell. T cells and B cells make up most of the normal lymphocytes that protect you from infection, and lymphocytic leukemia can be either T or B cell leukemia. The cell type dictates the therapy your doctor suggests.
  • Myelogenous Leukemia Myelogenous leukemia, also known as myeloid leukemia, affects myeloid cells, which mature into other types of white blood cells (such as neutrophils, the white blood cell that helps protect us from bacterial infections and which makes up pus), red blood cells, or platelets. (4,6)

Types of Leukemia

There are four main types of leukemia, which are grouped based on which blood cells they affect and whether they are acute or chronic:

Rarer forms of leukemia (such as hairy cell leukemia) and preleukemic diseases (such as myelodysplastic syndromes and myeloproliferative disorders) also exist. A subset of the preleukemic disorders progress to AML. (4)

Your doctor can run certain tests to help determine what type of leukemia you have. Being educated about your specific type of cancer can empower you to make better decisions about your care.

Learn More About Leukemia Types

Acute Lymphocytic Leukemia (ALL): Fast-Growing but Rare in Adults

Acute lymphocytic leukemia (ALL) causes your bone marrow to produce large amounts of abnormal B and T cells, which don’t leave any room for healthy cells. ALL makes up 2 percent of leukemias, is more common in men and white people, and is the most common cancer type in children, according to StatPearls. People with ALL may be prone to easy bruising and bleeding, fatigue, and frequent infections. ALL can spread to different parts of the body, like your lymph nodes, liver, spleen, brain, spinal cord, and testicles. This type of leukemia can be treated with two to three years of chemotherapy and stem cell transplants.

Acute Myeloid Leukemia (AML): A Common Form of Leukemia

Acute myeloid leukemia is a fast-growing cancer that begins in the bone marrow — a spongy tissue inside certain bones. It affects myeloid cells in the bone marrow, which normally give rise to red blood cells, white blood cells, and platelets. Typical symptoms of the disease include fatigue, weakness, pale skin, shortness of breath, and bruising. Treatments range from chemotherapy and stem cell transplantation to targeted therapies.

Learn More About Acute Myeloid Leukemia

Chronic Lymphocytic Leukemia (CLL): A Slow-Growing Cancer

Of all the leukemias diagnosed in adulthood, CLL is the most common, affecting nearly 21,000 people each year. This form of leukemia rarely occurs in children and tends to be diagnosed most commonly in older adults. A variety of treatments are used to fight CLL, depending on the pace at which it is progressing. They range from chemotherapy and immunotherapy to a watch-and-wait approach. Small lymphocytic leukemia (SLL), a variant of CLL, is treated in a similar fashion, but in SLL, most of the cancerous cells live in the lymph nodes instead of the bone marrow and blood.

Learn More About Chronic Lymphocytic Leukemia

Chronic Myelogenous Leukemia (CML): An Uncommon Form of Leukemia

Chronic myelogenous leukemia is much less common than other forms, only making up 15 percent of leukemia cases, according to the American Cancer Society (ACS). Also originating in the bone marrow, CML cells quickly fill that space and begin to spill into the blood. CML is most common in older adults and rare in children. This form of leukemia can come with no symptoms, and is often found through routine blood tests. The firstline treatment for CML is targeted therapy and many people experience long remissions.

Hairy Cell Leukemia: A Highly Treatable Cancer

This rare form of leukemia accounts for 1 to 2 percent of all cases of adult leukemia. Like other leukemias, it begins in the bone marrow, where blood cells are made. It affects B cells (a type of lymphocyte), a white blood cell that, when normal, helps the body fight infection. When cancerous, these B cells develop a distinctive hairy appearance. Though this form of leukemia is considered incurable, it is highly treatable and symptoms can be easily controlled with therapy. Some diagnosed with the disease may even be asymptomatic and, if they’re able to maintain a normal blood count, will not require therapy, according to the National Cancer Institute (NCI).

Learn More About Hairy Cell Leukemia

What Are The Common Symptoms of Leukemia?

Learn about the common symptoms of leukemia.
What Are The Common Symptoms of Leukemia?

Adult vs. Childhood Leukemia

Leukemia occurs more often in adults who are older than 55 years of age. But it’s also the most common cancer in children younger than 15. (2) ALL is the most common type of childhood cancer. It typically affects kids ages 3 to 5. Boys are diagnosed with ALL at a slightly higher rate than girls, and the disease is most common in Hispanic children. (11)

With the exception of ALL, the risk for most types of leukemia typically increases with age. Men are more likely than women to develop CML, CLL, and AML. (12)

RELATED: What Is Childhood Leukemia?

What Causes Leukemia?

The exact cause of leukemia isn’t known, but certain risk factors can up your chances of acquiring the cancer.

Children with Down syndrome are up to 30 times more likely to develop ALL, according to Leukaemia Care. Other inherited conditions, blood disorders, and even some common viruses like HIV or Epstein-Barr virus may raise a person’s risk for leukemia.

Environmental triggers are another possible culprit. Exposure to radiation, chemicals, pesticides, and cigarette smoke are linked to specific types of leukemia. Being treated with certain chemotherapy drugs can also increase your likelihood of later developing leukemia.

While there’s no way to completely evade leukemia, avoiding preventable risk factors may help you lower your chances of developing the disease.

Learn More About Leukemia’s Causes

Symptoms of Leukemia

Signs and symptoms vary depending on the type of leukemia you have. Some people with chronic leukemia don’t have symptoms for a while, whereas those with acute forms of the disease usually notice problems much sooner. Leukemia is sometimes hard to spot because the signs are vague and not specific.

Many of the general symptoms that people with leukemia experience overlap with those of common illnesses:

  • Bleeding
  • Bone pain
  • Bruising
  • Fatigue
  • Fever
  • Loss of appetite
  • Night sweats
  • Unexplained weight loss

Sometimes leukemia, or its treatment, can lead to complications, which come with their own set of symptoms:

  • Peripheral Neuropathy Some leukemia treatments can cause numbness, tingling, burning, and temperature changes to your extremities.
  • Kidney Damage Leukemias can cause your body to put out large amounts of protein and calcium, which can impair your kidneys.
  • Anemia Low red blood cell counts can cause fatigue, pale skin, dizziness, and trouble breathing.
  • Blood Clots The combination of cancer-fighting drugs and steroids can sometimes cause a clot to form. These clots can be dislodged to the heart or brain, causing symptoms of heart attack or stroke.

See your doctor if you have any complaints that are unusual, severe, or don’t go away. Your physician can help you find out what’s wrong and determine if your symptoms are caused by leukemia.

Learn More About Leukemia Symptoms

Diagnosing Leukemia

If your annual blood work comes back suggestive of leukemia, or you have been experiencing symptoms associated with this cancer, your healthcare provider will prescribe some further testing. Depending on your specific situation, your provider may order blood tests, imaging, or a biopsy to determine the type and stage of leukemia. This will allow better, more targeted treatment.

Blood Tests

Since leukemia is a cancer of the blood cells, your blood offers valuable clues to what’s going on. Your provider may prescribe one of these common blood tests:

  • Complete Blood Count (CBC) Measures the amount of red blood cells, white blood cells, and platelets in your blood, and can also look at the different types of white blood cells.
  • Comprehensive Metabolic Panel (CMP) Identifies the levels of electrolytes like sodium and potassium in your blood and can also measure kidney and liver function.
  • Prothrombin Time and International Normalized Ratio (PT/INR) Checks how well your blood is clotting.

Bone Marrow Aspiration Biopsy

Leukemias start in your bone marrow, so a biopsy of this area will often give your provider most of the information they need to know about your leukemia. During a bone marrow aspiration, you lie on a table on your side or stomach. The area is numbed, then a needle is placed into the bone to pull out (aspirate) a small amount of liquid bone marrow. After this, a larger needle is placed to remove a small piece of bone and marrow. Most patients feel a brief pain when marrow is removed, but some only feel pressure.

Lumbar Puncture

Leukemias can spread to the fluid around the brain and in the spinal cord, called cerebrospinal fluid, or CSF. A lumbar puncture, also known as a spinal tap, removes a small amount of CSF to check for leukemia cells.

Chromosome Tests

Chromosome tests allow your health team to examine the long strands of DNA in your cells. Pieces of chromosomes can sometimes mutate or even switch places. One such genomic alteration, called the “Philadelphia chromosome” appears in the majority of CML and some ALL cases, according to the Abramson Cancer Center.

Imaging

Imaging tests like X-rays, CT scans, and MRI scans allow your provider to see more clearly what’s going on in your body. Because leukemia rarely forms tumors, this method of diagnosis may not be used as frequently.

Lymph Node Biopsy

This diagnostic test is rarely needed in leukemias, as diagnosis is mostly done via bone marrow. But if needed, a small incision is made to remove the lymph node for testing. If the node is shallow, the biopsy can be done with local anesthesia, but for deeper nodes, general anesthesia is used.

Stages of Leukemia

Staging cancer is a way for doctors to identify the extent of the disease. Most cancers are staged by the size and spread of the tumors. Because leukemia occurs in blood cells, it’s staged differently.

Staging leukemia depends on the type you have, but doctors often consider the following factors when determining the stage and prognosis:

  • Your white blood cell or platelet count
  • Your age
  • Whether you have a history of blood disorders
  • If you have bone damage
  • If you have an enlarged spleen or liver
  • If you have chromosome mutations or abnormalities
  • If you’ve had chemotherapy for a different cancer in the past (7)

Leukemias are categorized or staged using different tools. For ALL, no staging tool is used. Instead, practitioners use test results to put it into subgroups like B-cell ALL and T-cell ALL.

AML has no standard staging system, but is classified by new diagnosis, in remission, refractory (didn’t respond to treatment), and recurrent. Subtypes of AML can be identified via two classification methods:

  • The French-American-British (FAB) Classification FAB classification puts AML into different categories numbered M0 to M7. Category assignment is based on where the leukemia cells originated and how mature they are.
  • World Health Organization (WHO) Classification The WHO classification method includes several categories that focus on chromosome changes, genetic abnormalities, and previous cancer treatment.

CLL is staged using a different tool depending on where you live:

  • Rai System This tool is unique to the United States. The stages range from Rai stage 0 to Rai stage 4, which indicate lymph node, spleen, or liver enlargement and red blood cell and platelet counts.
  • Binet Staging System This system is used all over Europe and includes three stages: Binet stage A, B, and C. Much like the Rai system, the Binet stages depend on lymph node and organ enlargement as well as blood counts.

Finally, CML is staged by measuring levels of blast (immature) cells in the blood and bone marrow:

  • Chronic Phase Blast cell levels under 10 percent of blood and bone marrow
  • Accelerated Phase Blast cell levels between 10 and 19 percent of blood and bone marrow
  • Blastic Phase Blast cell levels at or over 20 percent of blood and bone marrow

Treatment and Medication Options for Leukemia

Treatment options vary and depend on the type of leukemia you have, your age, your health status, and how advanced the cancer is.

Common approaches include the following treatments:

  • Chemotherapy This treatment uses specialized medications to kill cancer cells and shrink tumors. It can be given by mouth or through an IV.
  • Radiation Also used to target cancer cells and tumors, this therapy uses concentrated high doses of radiation to damage cancer cell DNA.
  • Immunotherapy A type of biological therapy, this treatment helps fight cancer by allowing your immune system to become more active and recognize the cancer cells to kill them. It is given through an IV.
  • Targeted Treatment Lab-developed proteins (monoclonal antibodies) and medications are used in this treatment to target cancer cells with less disruption of healthy cells. The medications can be given as capsules to swallow, and monoclonal antibodies are administered through an IV.
  • Stem Cell Transplantation This treatment is used to replace blood-making stem cells in the bone marrow that may have been destroyed during chemotherapy or radiation. These cells are administered through an IV and then travel to your bone marrow to begin making healthy blood cells.

In some cases of CLL, specifically, doctors will recommend a “watch and wait” approach until the cancer grows more. CLL is most often diagnosed in older adults, with an average age of 70 at diagnosis, according to the ACS. As its name implies, chronic lymphocytic leukemia is not a fast-moving cancer in most people. One study, published in February 2020 in Nature, suggests early treatment doesn’t necessarily lead to longer survival times for all CLL cases.

Complementary and supportive therapies can help you deal with the side effects of harsh treatments. Clinical trials are also an option if you want to try an experimental therapy that isn’t available as a mainstream option.

Choosing a treatment regimen isn’t always easy. That’s why it’s important to work with a doctor you trust.

Learn More About Leukemia Treatment

Side Effects of Leukemia and Treatment

The goal of leukemia treatment is to kill cancer cells, but many treatments involve some collateral damage. As healthy cells get taken out by cancer treatment, the following side effects can emerge:

  • Low Platelet Levels This treatment side effect caused by chemotherapy and targeted therapy can lead to nosebleeds, bleeding gums, and bruising.
  • Anemia Low red blood cell counts from chemotherapy and radiation therapy can cause fatigue, weakness, headaches, pale skin, and difficulty breathing. It can also make you feel cold, dizzy, and lightheaded.
  • Low Neutrophil Count When neutrophils can’t keep their numbers up, your body will be more prone to infection of all types.
  • Graft-Versus-Host Disease After a stem cell transplant, your body may reject the foreign cells. If this happens, you may experience a rash that spreads over the body, diarrhea, and jaundice from liver failure.
  • Leukemia Rashes Immunotherapy and targeted therapy can cause a dry rash on your skin that can also blister.
  • Radiation Skin Changes After radiation therapy, some report dry itchy skin that can peel and turn red or dark. Others develop sores that are wet, swollen, and painful.

If leukemia cell counts get very high, they can block the red blood cells carrying oxygen to your organs, which can cause headache, weakness, slurred speech, and confusion. This buildup can also cause joint and bone pain and abdominal swelling.

Leukemia Survivorship: Health Effects Down the Road

For many leukemia survivors, the struggle isn’t over when treatment ends.

Adults and children with this cancer often face physical and psychological issues months or even years after going into remission. The most common physical symptom in remission is fatigue, which sometimes lingers for months to years, according to the ACS. Some also report “chemo brain” which causes difficulties with memory during and after treatment. In remission, some experience symptoms of depression, anxiety, and insomnia.

Your risk of developing long-term effects from treatment depends on the type of therapy you received, your age, your overall health, your gender, and the duration of your treatment.

Regular follow-up appointments with your primary care physician and oncologist are vital for spotting any issues that could become serious.

Taking care of yourself, finding a good support system, and utilizing available resources can also help you optimize your daily life as a survivor.

Learn More About Leukemia Survivorship

Leukemia Prognosis

Treatment outcomes, or prognosis, for leukemia varies widely depending on leukemia type and stage. Overall, leukemia’s five-year survival rates have spiked, from 33.4 percent in 1975 to 70.9 percent in 2015, according to the NCI.

Acute Lymphocytic Leukemia Prognosis

Almost 90 percent of adults diagnosed with ALL go into remission with treatment. Although remission rates are high, 20 to 40 percent experience relapses. ALL has about a 70 percent five-year survival rate across all stages and patient ages.

Acute Myelogenous Leukemia Prognosis

The five-year survival rate for AML is about 30 percent, according to the Leukemia and Lymphoma Society, but on an individual level, survival depends on a collection of factors:

  • Age Rate of remission tends to be lower if your age at diagnosis is higher.
  • Spread If the leukemia has spread to the central nervous system, treatment can be more difficult.
  • Infection If you have an infection that affects your entire body, such as sepsis, prognosis is not as good.
  • History Previous cancer treatment can affect prognosis, and a relapse has a lower prognosis than a new diagnosis.

Chronic Lymphocytic Leukemia Prognosis

CLL claims a survival rate of 88 percent, according to the NCI, which is higher than any other leukemia type. And the earlier CLL is caught, the higher your chance for survival.

Chronic Myelogenous Leukemia Prognosis

CML survival rates have spiked since targeted therapies were introduced as a first-line treatment in 2003. Since then, five-year survival rates have climbed from 33 percent to more than 90 percent, and 10-year survival has reached approximately 84 percent, according to StatPearls.

Finding a Doctor

A hematologist-oncologist is a doctor who treats people with blood cancers. You can find a blood cancer specialist by asking your primary care physician for a recommendation or by contacting your community cancer center.

Additionally, the Leukemia and Lymphoma Society offers several resources to help you locate a specialist in your area. (8)

You might want to ask the following questions when deciding on a doctor:

  • Is the doctor licensed and board-certified?
  • Is the doctor a member of any professional societies?
  • How much experience does the doctor have in treating your type of leukemia?
  • How long will it take to wait for appointments?
  • What is the support system like? Will nurses and case managers be available to assist you?
  • What’s the best way to contact the physician?
  • Will my insurance company cover the leukemia treatment I receive under this doctor's care? (8)

Resources We Love

If you’ve recently been diagnosed with leukemia, it’s important that you and your family have access to resources that can help you understand, cope with, and recover from your condition. Here are our most recommended organizations, articles, and websites that provide information and support.

Leukemia and Lymphoma Society

The Leukemia and Lymphoma Society (LLS) was founded by the de Villiers family after the loss of their 16-year-old son to leukemia. Through research funding, policy change advocacy, and patient support, LLS states their mission is to cure leukemia and improve patients’ and families’ quality of life. They offer support groups, online chats, peer-to-peer support, financial support, and caregiver support. They also provide information on current clinical trials to patients who may be interested.

Mayo Clinic

Mayo Clinic is a wide-reaching not-for-profit medical group practice that treats 1.4 million patients from 150 countries, and provides health education to millions through their health content. Mayo also runs clinical trials, and you can look up any condition to find a trial near you.

American Cancer Society

The American Cancer Society (ACS) has been a mainstay of cancer education since its inception in 1913. The ACS provides assistance with transportation, lodging, and advice on next steps after diagnosis through their ACS CARES program. They offer a cancer support network and a 24/7 cancer helpline.

National Cancer Institute

As the federal government's primary agency for cancer research, the National Cancer Institute (NCI) offers a large library of health information, all backed by the latest studies. The NCI funds more cancer research than any other organization in the world. They also focus their efforts on training healthcare professionals to better identify and treat cancers. You can find NCI-supported clinical trials on their website.

City of Hope

City of Hope, previously known as Cancer Treatment Centers of America, seeks to tailor their cancer treatments to each individual patient. Through methods like advanced genomic testing and new treatment advances, City of Hope seeks to deliver precision cancer treatment through personalized medicine. Their Cancer Fighters program connects patients with others around the country who have experienced similar diagnoses.

Cancer Care

Cancer Care offers free professional support after leukemia diagnosis. This includes resource management, counseling, support groups, and educational workshops. Cancer care also offers financial assistance to those who need it. You can also listen to their Cancer Out Loud podcast to hear stories of commiseration and support.

Leukemia Research Foundation

The Leukemia Research Foundation funds leukemia research and offers an extensive online support community. They offer live, monthly Q&A sessions with leukemia experts so you can ask any question you have. In addition to an online community, you can be matched with a mentor or mentee for peer support. They can also offer financial assistance grants for patients who live in Illinois.

Editorial Sources and Fact-Checking

Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.

Resources

  1. White Blood Cell. National Cancer Institute.
  2. Leukemia — Patient Version. National Cancer Institute.
  3. Leukemia. Leukemia and Lymphoma Society.
  4. Leukemia. Mayo Clinic. September 21, 2022.
  5. Deleted September 5, 2023.
  6. Leukemia. American Society of Hematology.
  7. Leukemia Stages. Cancer Treatment Centers of America. May 26, 2022.
  8. Choosing a Blood Cancer Specialist. Leukemia and Lymphoma Society.
  9. Deleted September 5, 2023.
  10. Deleted September 5, 2023.
  11. Acute Lymphoblastic Leukemia (ALL). St. Jude Children’s Research Hospital.
  12. Risk Factors for Leukemia. Cancer Treatment Centers of America. May 26, 2022.
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