Blood sample with a mix of healthy and abnormal cells

What is acute leukemia?

Canadian Cancer Society logo appears above the video title, “What is acute leukemia?” This video is part of the Cancer Basics series.

Narrator: What is acute leukemia?

The narrator appears on screen. She is a hematologist.

Narrator: Leukemia is a cancer of blood-forming cells.

A couple appears with the hematologist, one of them looks sick. Then a mother and her sick child appear on screen as well.

Narrator: To understand this type of cancer, let’s look at how blood cells develop.

The hematologist, couple and mother and child move off screen. An outline of a body appears on screen. There is a cross-section illustration of the femur (thigh bone) showing the bone marrow in the centre of the bone.

Narrator: All the cells in our bodies start as stem cells. They’re made in the bone marrow, the spongy material in the centre of most of our bones.

The illustration zooms in to show stem cells in the bone marrow.

Narrator: Stem cells are very basic cells that grow and develop so they can do specific jobs. They can become blood cells, or muscle cells, or nerve cells, or any other type of cell.

Illustration of the stem cells in the bone marrow shifts to the right. The hematologist appears at her desk.

Narrator: There are 2 types of stem cells that make blood cells. One is called myeloid and the other is called lymphoid.

Two stem cells appear above the hematologist. The one on the left is a myeloid stem cell. The one on the right is a lymphoid stem cell. 

Narrator: In the first step of blood cell formation, stem cells develop into blast cells – or just blasts. 

Both the myeloid and lymphoid stem cells begin to move. The myeloid stem cell transforms into a blue blast cell. The lymphoid stem cell transforms into an orange blast cell.

Narrator: Blast cells then develop into different types of blood cells. 

The two stem cells move apart. Two more blue (myeloid) blast cells appear. They transform into a red blood cell, a platelet and a white blood cell.

Narrator: Blasts from myeloid stem cells will become red blood cells, platelets, or different types of white blood cells. 

Next to the red blood cell, the outline of a body showing the lungs appears. The animation shows that red blood cells travel from the lungs to other parts of the body and back again.

Narrator: Red blood cells carry oxygen to tissues all over the body. 

Next to the platelet, a hand appears. The animation shows a cut on the hand that is bleeding and then stops.

Narrator: Platelets help blood to clot.

Next to the white blood cell, an animation shows white blood cells attacking bacteria cells.

Narrator: The different types of white blood cells help fight infection and destroy abnormal cells, including cancer cells.

The orange (lymphoid) blast cell appears on screen. It transforms into a white blood cell. The white blood cell moves next to the animation of the white blood cells attacking bacteria cells.

Narrator: Blasts from lymphoid stem cells will develop into just one type of white blood cell called a lymphocyte.

The scene changes and the hematologist appears. Next to her is a blue (myeloid) blast cell. It transforms into an abnormal (brown) blood cell.

Narrator: Leukemia is when blood cells don’t form and behave normally. There are many types of leukemia. They are named based on the type of blood cell that is abnormal and how quickly the leukemia develops. 

Some healthy blood cells appear next to the abnormal (brown) blood cell. There are now 3 red blood cells, 3 platelets, 2 white blood cells and one abnormal blood cell. A calendar appears next to the cells. The pages turn slowly at first and then more quickly.

Narrator: Acute leukemias develop very quickly. The blast cells don’t mature into healthy blood cells. They make many copies of themselves, which build up in the bone marrow. 

The sick man from the couple appears on the screen. Next to him is a sample of blood cells showing abnormal (brown) cells mixed in with healthy blood cells.

Narrator: As more and more abnormal blast cells build up, they crowd out healthy blood cells so they can’t do their jobs properly.

The illustration of the blood cells zooms out to show that there are many abnormal cells mixed in with the healthy blood cells. The man appears to become sicker.

Narrator: There are 2 main types of acute leukemia. 

The blood sample disappears and the man moves to the middle of the screen.

Narrator: Acute myeloid leukemia, or AML, develops most often in adults. But it sometimes affects children.

The man disappears and the sick child appears on screen.

Narrator: Acute lymphoblastic leukemia, or ALL, is the most common type of leukemia diagnosed in children. Only a small number of adults are diagnosed with ALL each year.

The sick child disappears. The sick man appears on screen. He is seated in a chair. His partner is standing next to him, comforting him.

Narrator: Acute leukemia can make people very sick. They may have a fever, find it hard to breathe and will be very tired. They may also bleed and get infections easily.

Illustrations of a thermometer and a nosebleed appear next to the couple. The couple and illustrations disappear. The hematologist appears on screen. She is seated at a table with a microscope and blood samples in front of her.

Narrator: Leukemia is usually diagnosed using simple blood tests. The healthcare team may then do a bone marrow biopsy to look at the type and number of abnormal cells in the blood and bone marrow. 

A vial of blood appears next to the hematologist. An illustration shows that the sample of blood has a mix of healthy blood cells and abnormal (brown) blood cells.

Narrator: All of this information tells the team what type of leukemia it is and how best to treat it.

A thought bubble appears next to the hematologist. Inside is a pill bottle and an IV bag with chemotherapy.

Narrator: If you have an acute leukemia, you will need to be treated right away. Chemotherapy is the main type of treatment for acute leukemias.

The hematologist, blood sample and chemotherapy drugs disappear. The sick man appears in a hospital bed. His partner is seated next to him. The hematologist appears on screen, then a nurse next to her.

Narrator: Your healthcare team can give you more information about acute leukemia and your treatment options.

The scene zooms out to show more of the room. An oncologist and social worker appear next to the hematologist and nurse. 

Narrator: The Canadian Cancer Society is also here to help. Visit or call us at 1-888-939-3333.

Canadian Cancer Society logo appears above the contact number and website. The BMO bank logo appears below as a sponsor of the Cancer Basics videos.