Acute myeloid leukemia is a blood cancer that develops quickly in bone marrow

Acute myeloid leukemia (AML) is a type of blood cancer where bone marrow produces too many immature white blood cells called blasts. These blasts multiply rapidly and crowd out healthy blood cells, leaving the body unable to fight infection, carry oxygen, or stop bleeding. The word "acute" means the disease develops and worsens quickly—over days or weeks rather than months or years.

In a healthy person, bone marrow makes white blood cells, red blood cells, and platelets in a controlled way. In AML, something goes wrong with a single myeloid cell (a type of white blood cell precursor), causing it to divide uncontrollably. The blasts accumulate in the bone marrow and spill into the bloodstream, crowding out the normal cells your body needs.

AML can develop in adults and children, though it is more common in people over 65. It is not contagious and cannot be caught from another person. The disease is serious and requires prompt treatment, but many people respond well to therapy.

Key Takeaways

  • AML occurs when bone marrow produces too many immature white blood cells that multiply rapidly and prevent normal blood cells from forming.
  • Symptoms include unusual bruising or bleeding, fatigue, shortness of breath, frequent infections, and bone or joint pain.
  • Doctors diagnose AML by examining a bone marrow sample under a microscope and running blood tests and genetic studies.
  • Treatment usually begins within days of diagnosis and typically involves chemotherapy, targeted drugs, or stem cell transplant depending on the person's age and overall health.
  • Survival rates and treatment outcomes have improved significantly over the past decade, especially for younger adults.

How AML develops and who is at risk

AML starts when a genetic change occurs in a single myeloid cell in the bone marrow. This change is not inherited—it happens by chance during a person's lifetime. Doctors do not yet fully understand why this change occurs in some people and not others, but certain factors make it more likely.

People over 65 have the highest risk of developing AML. Other risk factors include previous chemotherapy or radiation treatment for another cancer, exposure to benzene (a chemical used in manufacturing), smoking, and certain blood disorders like myelodysplastic syndrome. People with Down syndrome also have an increased risk. Having a risk factor does not mean a person will develop AML—many people with risk factors never do.

Symptoms that may appear suddenly

Because AML develops quickly, symptoms often appear over days or weeks. Many symptoms result from the shortage of normal blood cells. A shortage of red blood cells causes fatigue and shortness of breath. A shortage of platelets (cells that help blood clot) causes unusual bruising, nosebleeds, or bleeding gums. A shortage of healthy white blood cells makes infections more likely, leading to fever, chills, or mouth sores.

Other symptoms include bone or joint pain, swollen lymph nodes, swollen spleen or liver, and pale skin. Some people have no symptoms and discover AML by chance during a blood test for another reason. If symptoms appear suddenly or persist for more than a few days, a doctor should evaluate them.

How doctors diagnose AML

Diagnosis begins with a blood test. The doctor looks at a sample under a microscope to count the types of cells present. If too many blasts are visible, the next step is a bone marrow biopsy—a procedure where the doctor uses a needle to remove a small sample of bone marrow, usually from the hip bone. This sample is examined under a microscope to confirm AML and determine how many blasts are present.

The doctor also sends the bone marrow sample to a laboratory for cytogenetics and molecular testing. These tests look for specific genetic changes in the leukemia cells. The genetic makeup of the leukemia helps doctors predict how the disease will behave and which treatments are most likely to work. This information is crucial for planning treatment.

Additional tests may include a chest X-ray to check for infection or leukemia in the lungs, an ultrasound or CT scan to look at the spleen and liver, and a lumbar puncture (spinal tap) to check whether leukemia cells have reached the fluid around the brain and spinal cord. These tests help doctors understand the full extent of the disease.

Stages and risk categories

Unlike many cancers, AML is not staged using a numbered system. Instead, doctors classify AML into risk categories based on the genetic changes found in the leukemia cells. These categories—favorable, intermediate, and adverse—help predict how the disease will respond to treatment and what the likely outcome is.

The percentage of blasts in the bone marrow also matters. If more than 20 percent of cells in the bone marrow are blasts, the diagnosis is AML. If the percentage is lower but other features of AML are present, the diagnosis may still be AML. The specific genetic changes and the person's age and overall health all factor into the treatment plan.

Treatment options and what to expect

Treatment usually starts within days of diagnosis. The goal is to destroy the leukemia cells and allow normal bone marrow to recover. The main treatment is chemotherapy, which uses drugs to kill rapidly dividing cells. The standard chemotherapy combination for AML is called "7+3"—seven days of one drug combined with three days of another.

Newer options include targeted drugs that attack specific genetic changes in the leukemia cells, and hypomethylating agents, which are drugs that work differently than traditional chemotherapy. For younger, healthier patients, a stem cell transplant (also called a bone marrow transplant) may be recommended after initial treatment to reduce the risk of relapse.

Treatment is intensive and requires hospitalization. During chemotherapy, the bone marrow stops producing blood cells temporarily, so patients receive transfusions of red blood cells and platelets. Patients also receive antibiotics to prevent infection. Recovery of normal blood cell production takes weeks. Most people need multiple rounds of treatment over several months.

Life after treatment and follow-up care

After initial treatment, patients have regular blood tests and bone marrow biopsies to check whether the leukemia has gone into remission (a state where no leukemia cells can be detected). If remission is achieved, ongoing treatment may continue to prevent relapse, or the patient may enter a monitoring phase with regular check-ups.

Long-term side effects of treatment can include heart problems, lung problems, infertility, and a small risk of developing another cancer years later. A doctor who specializes in cancer care (an oncologist) will monitor for these effects and manage them if they occur. Many people live for years after AML treatment, and some are cured.

Frequently Asked Questions

Is AML hereditary or contagious?

AML is neither hereditary nor contagious. The genetic change that causes AML happens by chance in a single cell during a person's lifetime and is not passed down from parents to children. You cannot catch AML from another person.

What is the difference between AML and other types of leukemia?

AML affects myeloid cells and develops quickly. Chronic myeloid leukemia (CML) also affects myeloid cells but develops slowly. Acute lymphoblastic leukemia (ALL) affects lymphoid cells and develops quickly. Chronic lymphocytic leukemia (CLL) affects lymphoid cells and develops slowly. The type determines which treatments work best.

Can children get AML?

Yes, AML can develop in children, though it is less common in children than in adults. Children with AML are usually treated at specialized pediatric cancer centers. Treatment approaches and outcomes for children differ from those for adults.

What happens if AML comes back after treatment?

If leukemia returns after remission, it is called relapsed AML. A second round of treatment may be recommended, which could include different chemotherapy drugs, targeted drugs, or a stem cell transplant if one was not done initially. Doctors will discuss options based on how long remission lasted and the person's current health.

How long does AML treatment take?

Initial intensive chemotherapy typically takes several months, with patients spending weeks in the hospital. If a stem cell transplant is planned, the entire process from diagnosis to transplant recovery can take six months to a year. After that, ongoing monitoring continues for years.