What is leukemia?

Leukemia is cancer of the blood cells. Blood cells and platelets are produced in the bone marrow. In leukemia, some new white blood cells (WBCs) fail to mature properly. These immature cells continue to reproduce at a rapid rate, crowding out healthy cells and producing a host of symptoms.

Leukemia is the most common type of childhood cancer, affecting about 4,000 children a year in the United States.

The cause of childhood leukemia cannot be determined in most cases. The symptoms of leukemia can vary from one child to another. The symptoms of chronic leukemia generally develop slowly, but those of acute leukemia can appear suddenly. Some symptoms can be easy to confuse with those of common childhood diseases. Having some of these listed symptoms doesn’t necessarily mean your child has leukemia.

The common symptoms of childhood leukemia include the following:

Bruising and bleeding

A child with leukemia may bleed more than expected after a minor injury or nosebleed. The child may also bruise easily. They may have small red spots on the skin, or petechiae, which occur due to tiny blood vessels that have bled.

The blood’s ability to clot depends on healthy blood platelets. In a child with leukemia, a blood test will reveal an abnormally low platelet count.

Stomachache and poor appetite

A child with leukemia may complain of a stomachache. This is because leukemia cells can accumulate in the spleen, liver, and kidneys, causing them to enlarge. In some cases, a doctor may be able to feel the enlarged abdominal organs. The child may also have a poor appetite or be unable to eat a normal amount of food. Weight loss is common.

Trouble breathing

Leukemic cells can clump around the thymus, which is a gland at the base of the neck. This can cause dyspnea, or difficulty breathing. Breathing trouble can also result from swollen lymph nodes in the chest that push up against the windpipe. A child with leukemia may cough or wheeze. Painful breathing is a medical emergency.

Frequent infections

WBCs are necessary to fight off infection, but the immature WBCs of leukemia are unable to perform that function properly. A child with leukemia may experience frequent or prolonged bouts of viral or bacterial infections. The symptoms include coughing, fever, and runny nose. These infections often show no improvement, even with the use of antibiotics or other treatment.


Lymph nodes filter the blood, but leukemia cells sometimes collect in lymph nodes. This can cause swelling:

MRI and CT scans may reveal swollen lymph nodes of the abdomen or inside of the chest.

An enlarged thymus can press on a vein that transports blood from the arms and head to the heart. This pressure can cause blood to pool and lead to swelling of the face and arms. The head, arms, and upper chest may take on a bluish-red color. Other symptoms include a headache and dizziness.

Bone and joint pain

The body produces blood in the bone marrow. Leukemia causes blood cells to reproduce at an accelerated rate, leading to severe overcrowding of blood cells. This buildup of cells can lead to aches and pains of the bones and joints. Some children with leukemia may complain of lower back pain. Others may develop a limp due to pain in the legs.


Red blood cells (RBCs) help to distribute oxygen throughout the body. Overcrowding makes it difficult to produce enough RBCs. This leads to a condition called anemia. The symptoms include fatigue, pale skin, and rapid breathing. Some children also report feeling weak or lightheaded.

If your child has a reduction in blood flow to their brain, they may slur their speech. A blood test will show if your child has an abnormally low RBC count.

Having some of these symptoms doesn’t necessarily indicate the presence of leukemia. Several forms of childhood leukemia exist, and many factors impact the outlook. Early diagnosis and prompt treatment can improve outcome. Talk to your child’s doctor if you’re concerned about any of the symptoms your child has developed.

Survival rates for some forms of childhood leukemia have risen over time, and improvements in treatment point to a better outlook for children diagnosed today.