What are the types of leukemia?
Leukemia has several types. They include:
- Acute lymphoblastic leukemia
- Acute myeloid leukemia
- Chronic lymphocytic leukemia
- Chronic myeloid leukemia
- Hairy cell leukemia
The type depends on two things: which blood cell became cancer, and whether the cancer grows quickly or slowly. Acute means fast growing. Chronic means slow growing. Lymphocytic and lymphoblastic point to the lymphoid line of white blood cells. Myeloid points to the other main line. Cross those two choices and you get the four common names. Hairy cell leukemia is a rarer chronic type, named for the way the cells look under a microscope.
Because of this, two people who both "have leukemia" may have almost nothing in common.
Who gets it
Leukemia occurs most often in adults older than 55. It is also the most common cancer in children younger than 15, and the childhood types are treated on their own protocols.
The American Cancer Society projects 67,790 new leukemia cases and 23,910 deaths in the United States in 2026, and SEER, the federal cancer statistics program, republishes them. That is 3.2% of new cancer diagnoses and 3.8% of cancer deaths. SEER's own measurements put the median age at diagnosis at 68 and five-year relative survival across all types at 68.6% for people diagnosed between 2016 and 2022, though that single figure hides enormous differences between the types.
Why the exact type changes everything
Chronic myeloid leukemia is the clearest example. Nearly all cases carry a specific chromosome change, in which the ABL1 gene from chromosome 9 joins the BCR gene on chromosome 22. The result is called the Philadelphia chromosome, and it creates a BCR::ABL1 fusion gene. That gene tells the marrow to make a protein called tyrosine kinase, which pushes too many stem cells into becoming white blood cells.
Knowing that made a class of drugs possible. Tyrosine kinase inhibitors block the enzyme directly. Five are approved for CML: imatinib mesylate, dasatinib, nilotinib, bosutinib, and asciminib. None of them treats the other leukemias.
CML is also described in phases, counted by blast cells, the immature blood cells that crowd out healthy ones. Chronic phase means fewer than 10% blasts in blood and marrow. Accelerated phase means 10% to 19%. Blastic phase means 20% or more.
Acute myeloid leukemia works differently again. The NCI is blunt that AML must be treated right away. One subtype, acute promyelocytic leukemia, has its own regimen built around all-trans retinoic acid and arsenic trioxide rather than standard chemotherapy alone.
Symptoms and urgency
Symptoms of acute leukemia often appear only 4 to 6 weeks before diagnosis. They include weakness or tiredness, fever, infection, paleness, and bleeding or easy bruising.
If you have been diagnosed with an acute leukemia, treat fever as an emergency rather than a nuisance. Call your team the same hour for a temperature of 100.4 °F (38 °C) or higher, or for chills, since low white cell counts make infection dangerous fast.
What to ask for
Ask for the full name of your leukemia in writing, including any subtype. "Leukemia" alone will send you to the wrong information and the wrong support groups.
Then ask which genetic tests were run on your blood or marrow and what they showed. Ask whether treatment needs to start now or whether there is time to seek a second opinion. For acute types the honest answer is often that there is not, and knowing that changes how you spend the next few days.
Sources
Want the full picture? Read our complete explanation: What Is Leukemia? Blood Cancer Explained
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