AML: symptoms and diagnosis
The symptoms of acute myeloid leukemia often start like ordinary tiredness or a cold, but build up over a few weeks. This topic explains, calmly and clearly, which signs to watch for, when to seek urgent help, in what order the diagnosis is made and roughly what the results mean.
01Short answer
02Simple explanation
AML starts in the bone marrow — the “factory” where blood cells are made. Immature myeloid cells, called blasts, multiply quickly and leave no room for healthy cells. Almost every symptom follows from this: the blood runs short of red cells, working white cells and platelets.
The first signs are often vague: unexplained tiredness, weakness, breathlessness on the stairs, pale skin. Later there may be repeated fevers and infections that linger, bruises that appear easily, tiny red spots on the skin (petechiae), and nosebleeds or bleeding gums. Some people have bone pain, loss of appetite and weight loss.
Some signs are less common but typical of AML: swollen gums, lumps or patches in the skin (especially in monocytic subtypes), or a heavy feeling under the left ribs (an enlarged spleen). Having these signs does not mean you have AML — most of them have other, simpler causes. That is why only tests can decide.
The diagnosis is made step by step. First comes an ordinary complete blood count and a blood smear under the microscope. If blasts or unexplained changes are found, the bone marrow is examined. The lab then works out which cell family the blasts belong to and which genetic changes they carry.
Genetic results sometimes take a few days and sometimes a week or two. The wait can be hard, but it is not wasted time: doctors use this information to choose the treatment that suits you best. Meanwhile, protection from infection, transfusions when needed and attention to symptoms continue.
03Scientific explanation
On the blood count, the white cell count may be high, normal or low — AML does not always mean “too many white cells”. There is usually anemia and thrombocytopenia, and neutrophils are low. The smear may show myeloblasts; rod-shaped Auer rods inside them point to a myeloid origin. Blood chemistry (LDH, uric acid, potassium, phosphate, creatinine, liver tests) reflects the leukemia burden and the risk of tumour lysis syndrome, while clotting tests (PT, aPTT, fibrinogen, D-dimer) look for signs of DIC. A clotting disorder raises the suspicion of APL, in which case treatment starts immediately.
A bone marrow aspirate and trephine biopsy are the foundation of the diagnosis. By the classic threshold, blasts making up ≥20% of the marrow or blood means AML. However, with defining genetic changes — such as PML::RARA, RUNX1::RUNX1T1, CBFB::MYH11, an NPM1 mutation or KMT2A rearrangements — the WHO 2022 classification has largely removed the blast threshold, while ICC 2022 usually requires ≥10%; ICC also groups some cases with 10–19% blasts as “MDS/AML”. Flow cytometry shows the myeloid markers on the blasts: CD13, CD33, CD117 and MPO; the immaturity markers CD34 and HLA-DR; and CD14, CD64 and CD11b with monocytic differentiation. This profile later serves as the “baseline picture” for MRD monitoring.
Cytogenetics: a conventional karyotype (at least 20 metaphases analysed) reveals chromosome changes such as t(8;21), inv(16), t(15;17), −7, del(5q) or a complex karyotype; FISH can confirm key rearrangements faster. Molecular tests: ELN 2022 recommends getting results for FLT3 (ITD and TKD), NPM1, IDH1 and IDH2 as quickly as possible — ideally within a few days — because they influence whether a targeted drug is added to the first treatment. A broad NGS panel looks for mutations such as CEBPA, TP53, ASXL1, RUNX1, DNMT3A, TET2 and the splicing genes (SRSF2, SF3B1, U2AF1, ZRSR2).
Together, these data define the subtype (under WHO 2022 or ICC 2022) and the ELN 2022 risk group — favourable, intermediate or adverse. Before treatment there is usually a heart check (an echocardiogram, because of anthracyclines), screening for hepatitis B/C and HIV, a pregnancy test and, if a transplant might be considered, HLA typing of the patient and siblings; fertility preservation is discussed. A spinal fluid test is not routine in AML — it is usually done only if there are neurological symptoms. Some mutations (for example DDX41, RUNX1 or CEBPA) can be inherited; genetic counselling is recommended in that case.
04What happens in the body?
Symptoms that need urgent help
Contact your doctor straight away or call emergency services if: you have a temperature of 38 °C or higher or shivering (especially if your blood counts are known to be low); bleeding will not stop, or there is blood in your urine, stool or vomit; petechiae or large bruises are spreading quickly; you are breathless at rest, have chest pain or faint; you have a severe headache, confusion, changes in vision or speech. With a very high white cell count, these symptoms can signal an emergency called leukostasis.
In what order are the tests done?
Usually: a doctor’s examination and your history → complete blood count → blood smear → blood chemistry and clotting tests → bone marrow aspirate and biopsy → flow cytometry → cytogenetics (karyotype, FISH) → molecular tests (rapid FLT3/NPM1/IDH first, then a broad NGS panel). Tests to prepare for treatment run alongside. Many centres take all samples during one marrow procedure so it does not have to be repeated.
What do the results roughly mean?
The blast percentage confirms the diagnosis, flow cytometry shows the blasts are myeloid, and genetics tells you “which AML” it is. For example, t(8;21) or inv(16), or an NPM1 mutation without FLT3-ITD, usually fall into a more favourable group, while a TP53 mutation or a complex karyotype fall into a less favourable one. A risk group is not a verdict: it guides the treatment plan, especially the decision about a transplant after remission.
While you wait for results
For many people who are stable, doctors can wait a few days for key genetic results so the first treatment can be chosen more precisely. During this time it is important to watch for signs of infection, report any fever immediately and follow your team’s advice. If the white cell count is very high, treatment may start at once — even before the genetic results.
Questions you can ask your doctor
What exact subtype of AML do I have? Has APL been ruled out? Which genetic and molecular results are ready, which are pending and when will they come? What is my ELN risk group and how does it affect the plan? Do I need to start treatment before the results? Is there a clinical trial that suits me? Should my brothers and sisters have HLA typing? Whom do I call at night if I get a fever?
Make room for your feelings too
The days around a diagnosis are usually fast and exhausting: many tests, new words, decisions. Write your questions down, bring someone close to appointments, and never hesitate to ask again about a word you did not understand. The information here does not replace a conversation with your doctor — it is here to help you prepare for it.
05AML: from symptom to precise diagnosis
An AML diagnosis usually takes shape in four steps.
06Key tests in AML and typical findings
| Test | What does it check? | What is often seen in AML? |
|---|---|---|
| Complete blood count | Red cells, white cells, platelets | Anemia, thrombocytopenia; white cells may be high, normal or low |
| Blood smear | How the cells look under the microscope | Myeloblasts, sometimes Auer rods |
| Clotting tests | PT, aPTT, fibrinogen, D-dimer | Usually normal; signs of DIC may point to APL or some monocytic forms |
| Bone marrow | Blast percentage and marrow structure | Usually ≥20% blasts; fewer in certain genetic types |
| Flow cytometry | Surface and internal cell markers | CD13, CD33, CD117, MPO; often CD34, HLA-DR |
| Karyotype and FISH | Chromosome changes | For example t(8;21), inv(16), t(15;17), −7, complex karyotype |
| Molecular tests / NGS | Gene mutations | FLT3, NPM1, IDH1/2, CEBPA, TP53, ASXL1, RUNX1 and others |
* This table is general information; the exact set of tests may differ slightly between centres. Discuss your own results with your hematologist.
07Key terms
- Blast
- An immature blood cell in the bone marrow.
- Petechiae
- Tiny red spots on the skin caused by a shortage of platelets.
- Auer rod
- A rod-shaped structure seen in myeloblasts; it points to a myeloid origin.
- Leukostasis
- Impaired blood flow caused by a very high white cell count; an emergency.
- DIC
- Disseminated intravascular coagulation — clotting and bleeding problems at the same time.
- Flow cytometry
- A lab method that recognises cells by their surface markers.
- Karyotype
- An analysis of a cell’s chromosomes under the microscope.
- NGS
- Next-generation sequencing — studying many genes in a single test.
- ELN risk group
- A risk classification based on genetic findings (favourable, intermediate, adverse).
- HLA typing
- A tissue-matching test used to find a suitable donor for a transplant.
08Key points
- AML symptoms come from a shortage of healthy blood cells and usually build up over weeks.
- Main signs: tiredness, pallor, fever, infections, bruising and bleeding.
- Fever, bleeding that will not stop, breathlessness or confusion need urgent attention.
- The white cell count is not always high — it can be normal or low.
- The diagnosis is confirmed with a bone marrow examination and flow cytometry.
- Genetic tests define the subtype and the ELN risk group.
- Some results are ready within days, others take a week or two.
- Write down your questions and go through the results with your hematologist.
09Frequently asked questions
Can I have AML if my blood count is normal?
Acute leukemia with a completely normal blood count is very rare, because AML usually changes the blood values. But the changes are sometimes mild. If symptoms continue, your doctor may repeat the test or order further investigations.
Is a bone marrow test painful?
The procedure is done under local anaesthetic, and many centres also offer a sedative. You may feel a short, pulling pain as the needle enters the bone and during aspiration. The whole procedure usually takes 20–30 minutes, and there may be mild soreness for a day or two afterwards.
Why wait for genetic results?
In some AML subtypes a targeted drug is added to the first treatment (for example with an FLT3 mutation). Rapid tests matter for this decision. If you are not stable, doctors may start treatment without waiting.
Why is APL checked separately?
APL is a special form of AML: it carries a serious risk of bleeding but responds very well to different drugs. So clotting tests and a PML::RARA test are done early, and treatment starts immediately if APL is suspected.
Will they test my spinal fluid?
In AML this is not a routine test. It is usually done only if there is headache, a change in vision or other neurological symptoms, and occasionally in specific high-risk situations.
Can I get copies of my results?
Yes, most centres allow this. Keeping copies is useful if you want a second opinion or move to another centre. It is best to read the results together with your doctor.
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.
Which tests confirmed my AML diagnosis?
Which genetic results are we still waiting for?
Will my heart and other organs be checked before treatment?
How soon do we need to start treatment?
12Sources
- American Cancer Society. Signs and Symptoms of Acute Myeloid Leukemia (AML)
- American Cancer Society. Tests for Acute Myeloid Leukemia (AML)
- American Cancer Society. How Is Acute Myeloid Leukemia Classified?
- National Cancer Institute (NCI). Adult Acute Myeloid Leukemia Treatment (PDQ®) — Patient Version
- National Cancer Institute (NCI). Adult Acute Myeloid Leukemia Treatment (PDQ®) — Health Professional Version
- Blood Cancer United (formerly The Leukemia & Lymphoma Society). Acute myeloid leukemia (AML) diagnosis
- National Comprehensive Cancer Network (NCCN). NCCN Guidelines for Patients: Acute Myeloid Leukemia
- NHS. Acute myeloid leukaemia — Symptoms
- NHS. Acute myeloid leukaemia — Tests and next steps
- Cancer Research UK. Tests for acute myeloid leukaemia (AML)
- Blood (American Society of Hematology), 2022. Diagnosis and management of AML in adults: 2022 recommendations from an international expert panel on behalf of the ELN
- Annals of Oncology (ESMO), 2020. Acute myeloid leukaemia in adult patients: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up
- Leukemia (Nature) — WHO 5th edition. WHO Classification of Haematolymphoid Tumours: Myeloid and Histiocytic/Dendritic Neoplasms
- Blood (American Society of Hematology), 2022. International Consensus Classification of Myeloid Neoplasms and Acute Leukemias