← Back
Understanding leukemia

Understanding map

When you learn about leukemia, many topics are linked: the cell, DNA, the bone marrow, blood cells, the types of leukemia, tests, risk groups and treatment. This topic is the section’s “map”: it shows how the key ideas connect and where to read more about each step. Use it to find your bearings.

Last updated: ~6 min read
Translucent glowing cells and a DNA helix on a dark navy background, joined by fine lines of light like a constellation.
Figure 1.Concept: a map of knowledge, with glowing ideas linked to one another.

01Short answer

Picture the road to understanding leukemia as five steps. Step one is the body and blood: blood cells are made in the bone marrow from stem cells. Step two is from a cell to leukemia: a change in a cell’s DNA disrupts how it matures or divides, and a clone of abnormal cells appears. Step three is the types: leukemia can be acute or chronic, myeloid or lymphoid. Step four is diagnosis and risk: how the cells look, the markers on their surface and their genetic changes together give the exact diagnosis and risk group. Step five is treatment and beyond: the plan is built on this information, and the response is measured by remission and MRD. Each step helps you understand the next.

02Simple explanation

The body and blood. Blood links all the organs. Its cells, the red cells, white cells and platelets, are made in the bone marrow from stem cells. For this step: “Understanding the human body”, “Bone marrow” and “Types of blood cells”.

From a cell to leukemia. Every cell carries an instruction manual: its DNA. When a change (a mutation) happens in it, the cell may “forget” to mature or may divide without stopping. All the “offspring” of such a cell are called a clone, and that is what leukemia is.

Types. The earlier the stage at which the cell gets “stuck”, the more acute the leukemia. If the change starts in the myeloid line, the leukemia is called myeloid; if it starts in the lymphoid line, it is called lymphoid. This gives the main types: AML, ALL, CML and CLL.

Diagnosis and risk. Doctors look at the cells under a microscope, check the CD markers on their surface with flow cytometry, and examine chromosomes and genes with genetic tests. All of this together gives the exact diagnosis and the risk group.

Treatment and beyond. The plan is built around the type of leukemia, its genetic features and the person’s general health. Remission and MRD tests show that treatment is working, and then a period of follow-up begins.

03Scientific explanation

Modern classification rests on four keys: the 5th edition of the World Health Organization classification (2022) and the International Consensus Classification (ICC) published the same year define leukemias by how the cells look (morphology), their surface markers (immunophenotype), chromosome changes (cytogenetics) and gene mutations (molecular genetics), together with clinical information. Many types are now named after a specific genetic change.

Risk groups differ by type: in AML, the 2022 ELN recommendations sort genetic results into favourable, intermediate and adverse risk groups. In CML, the 2020 ELN recommendations track response to treatment by the BCR::ABL1 level. In CLL, the 2018 iwCLL criteria set out when to start treatment and how to assess response.

A prognosis is not a single number: according to the NCI, the outlook depends on the type of leukemia, its genetic features, age, general health and response to treatment. SEER statistics (5-year relative survival for all leukemias in the US is 68.6%) are averages for large groups and do not predict an individual future.

How to use the map: you do not have to read the topics in order. But when you meet a new term (for example, “FLT3 mutation” or “MRD-negative”), finding which step it belongs to on this map helps put the idea in its place. Then ask your doctor what it means for you.

04What happens in the body?

Steps 1–2: from the body to leukemia

The key questions at this stage are: what is a cell, what does DNA do, where and how are blood cells made, what is a mutation, and why can a change in just one cell lead to a whole disease? Understanding this explains why leukemia causes tiredness, infections and bleeding.

A glowing path running from left to right on a dark navy background: a shining DNA helix, translucent bone marrow tissue and cells flowing in a vessel.
Figure 2.From DNA to the bone marrow and blood: the main road to understanding leukemia.

Step 3: the “two axes” of types

Picture the types of leukemia as a table with two axes. One axis is speed: acute or chronic. The other is the cell line: myeloid or lymphoid. Where these axes cross sit the four main types: AML, ALL, CML and CLL. Acute promyelocytic leukemia, hairy cell leukemia and other rare forms each have their own special place on this map.

Step 4: the four keys of diagnosis

Morphology shows what the cell looks like, the immunophenotype shows which line it belongs to, cytogenetics shows changes in the chromosomes, and molecular tests show specific gene mutations. No single test is enough on its own; the results are read together, and the risk group is worked out from them.

Four translucent glowing beams shaped like keys pointing towards a centre on a dark navy background, with a softly shining cell in the middle.
Figure 3.The four keys of diagnosis together give the full picture.

Step 5: treatment and the road ahead

The treatment plan is built around the type, genetic features, age and general health: chemotherapy, targeted medicines, immunotherapy, a transplant or monitoring. The response is measured by remission and MRD tests. After remission come follow-up, checks for late effects and a return to everyday life.

Taking the map to your appointment

Before a visit, think about which step your question belongs to: “What type of leukemia do I have?” (step 3), “What do my genetic results show?” (step 4), “What is the aim of treatment?” (step 5). This makes the conversation clearer and helps you not to forget any important question.

05From a DNA change to treatment

The sequence of the key ideas (simplified).

DNA change — One blood cell’s instructions are disrupted.1DNA changeOne blood cell’s instructions are disrupted.
Clone — Abnormal cells multiply in the marrow.2CloneAbnormal cells multiply in the marrow.
Diagnosis — Four keys define the type and risk.3DiagnosisFour keys define the type and risk.
Treatment — Plan, response, remission and follow-up.4TreatmentPlan, response, remission and follow-up.
BearingsFind the place of every new term.
Detailed topicsA separate guide for each step.
Talk to your doctorGeneral knowledge plus your situation.

06The understanding map: steps and topics

StepKey ideaRead more
Body and bloodBlood cells are made in the bone marrow and serve the whole bodyUnderstanding the human body; Bone marrow; Types of blood cells
Cell and DNADNA is the cell’s instruction manual; changes to it disrupt the cellDNA, genes and proteins; Mutations
From a cell to leukemiaThe offspring of a changed cell form a cloneCell division and cell death
TypesAcute/chronic and myeloid/lymphoidTypes of leukemia: an overview
Diagnosis and markersMorphology, immunophenotype, cytogenetics, molecular testsBiomarkers; the “Diagnosis and tests” section
Risk and prognosisThe risk group affects how intensive treatment isClassification, risk groups and prognosis
Treatment and beyondPlan, remission, MRD, follow-upHow is a treatment plan made?; What is remission?

* This map is for general orientation. Your hematology team will explain the features of your own leukemia at each step.

07Key terms

Stem cell
The original cell from which all blood cells are made.
Mutation
A change in DNA.
Clone
A group of identical cells descended from one cell.
Blast
An immature blood cell; their number rises in acute leukemia.
Myeloid line
The line that produces red cells, platelets, granulocytes and monocytes.
Lymphoid line
The line that produces B, T and NK lymphocytes.
Morphology
How cells look under the microscope.
Immunophenotype
The set of markers on a cell’s surface.
Risk group
The group a leukemia falls into based on its expected response to treatment.
MRD
Measurable residual disease: a small number of leukemia cells found by sensitive tests.

08Key points

  • Leukemia can be understood in five steps: body, cell, type, diagnosis, treatment.
  • Blood cells are made in the bone marrow from stem cells.
  • Leukemia is a clone that starts with a DNA change in one cell.
  • Types are told apart by speed and cell line.
  • A diagnosis is made by reading the four keys together.
  • The risk group shapes the treatment plan.
  • Statistics do not predict an individual future.
  • Place every new term on the map, and ask your doctor.

09Frequently asked questions

In what order should I read the topics?

There is no fixed order. If you want to start with the basics, begin with the topics on the body and blood, then read about your own type of leukemia. If you have a specific question, go straight to the topic about it.

If I don’t understand everything, will my treatment go worse?

No. The success of treatment does not depend on how much biology you know. Knowledge simply helps reduce fear and lets you ask sharper questions. Asking about what you do not understand is completely normal.

Why does my leukemia have such a long name?

Modern classification names many leukemias after a specific genetic change. The long name gives the leukemia’s exact “address” and helps in choosing treatment. You can ask your doctor what each part of the name means.

Why do two people with the same type of leukemia get different treatment?

Within one type, genetic features, age, general health and response to treatment can differ. That is why plans are made for each person, and comparing yourself with someone else’s treatment is not always fair.

How do I find my own place on the map?

Ask your doctor to write down the full name of your diagnosis, your genetic results, your risk group and the aim of treatment. These four pieces of information place you precisely on the map.

Will this map change with new discoveries?

Yes, classification and treatment change as science moves on. We update the topics regularly based on trustworthy guidelines, but your doctor will always have the most current information.

10Questions for your doctor

Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.

  1. Which stage of the treatment journey am I at now?

  2. When and how will the next stage start?

  3. Which topics would be most useful for me to learn about now?

  4. Can I have a written summary of my treatment plan?

My questions

12Sources

  1. National Cancer Institute (NCI). What Is Cancer?
  2. National Cancer Institute (NCI). Leukemia — Patient Version
  3. MedlinePlus (U.S. National Library of Medicine). Leukemia
  4. American Society of Hematology (ASH). Leukemia
  5. American Society of Hematology (ASH). Blood Basics
  6. Leukemia (journal), 2022. Khoury JD et al. The 5th edition of the WHO Classification of Haematolymphoid Tumours: Myeloid and Histiocytic/Dendritic Neoplasms
  7. Leukemia (journal), 2022. Alaggio R et al. The 5th edition of the WHO Classification of Haematolymphoid Tumours: Lymphoid Neoplasms
  8. Blood (American Society of Hematology), 2022. International Consensus Classification of Myeloid Neoplasms and Acute Leukemias: integrating morphologic, clinical, and genomic data
  9. Blood, 2022. Diagnosis and management of AML in adults: 2022 recommendations from an international expert panel on behalf of the ELN
  10. Leukemia, 2020. European LeukemiaNet 2020 recommendations for treating chronic myeloid leukemia
  11. Blood, 2018. iwCLL guidelines for diagnosis, indications for treatment, response assessment, and supportive management of CLL
  12. National Cancer Institute (NCI). Understanding Cancer Prognosis
  13. National Cancer Institute (NCI). Questions to Ask Your Doctor about Your Diagnosis
  14. National Cancer Institute (NCI), SEER. Cancer Stat Facts: Leukemia
Medical disclaimerThis information is for educational purposes only and does not replace medical advice.
Last updated: ← Back to the list

Open the interactive site →