Many early symptoms of leukemia in children are also symptoms of common, less serious childhood illnesses. They can include flu-like illness, fatigue, lack of appetite, headaches, and frequent infections.

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Childhood leukemia represents about 24.9% of all new childhood cancer cases.

According to the National Cancer Institute in the United States, it is the most common type of cancer in children and teens, accounting for 1 out of 3 cancers affecting this age group. It affects more males than females, though not by a large margin.

Childhood leukemia is also slightly more common among Hispanic children and children who are white than among African American and Asian American children.

Leukemia affects the blood cells, most often, the white blood cells. White blood cells normally develop from stem cells in the bone marrow. When these cells grow abnormally, leukemia occurs.

A leukemia diagnosis can be frightening, but the survival rates continue to improve. This article explores the early symptoms of childhood leukemia, how to recognize its symptoms, and what to know about it.

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The earliest signs of leukemia can be hard to spot. They can also vary from child to child, as not all children with leukemia show the symptoms listed above.

Many of the symptoms are common and can indicate a range of illnesses. The doctor will perform various tests and assessments before making a diagnosis.

If a parent or caregiver notices any of the symptoms above, it is best to take the child to a doctor as soon as possible. A prompt diagnosis can ensure that the child receives the right treatment quickly.

Early symptoms may include:

Frequent infections

Children with leukemia have high white blood cell counts, but most of these cells are not functioning correctly. This is because abnormal cells replace healthy white blood cells.

White blood cells help protect the body by fighting off infections. For this reason, recurrent or persistent infections can indicate that a child does not have enough healthy white blood cells.

Bruising and bleeding

If a child bruises easily and experiences severe nosebleeds or bleeds from the gums, this may point to leukemia.

A child with this type of cancer will have a lack of platelets that help prevent bleeding.

Extreme fatigue

In rare cases, leukemia leads to very severe weakness and exhaustion that can result in slurred speech.

This occurs when leukemia cells collect in the blood, causing the blood to thicken. The blood may be so thick that circulation slows through small vessels in the brain.

Feeling generally unwell or experiencing frequent headaches

A child may not be able to describe their symptoms in detail, but they may appear to be generally ill. They may also experience frequent, unexplained headaches.

When the cause of a child’s illness is unclear, make an appointment with a doctor.


In a child with leukemia, swelling can affect various parts of the body, including:

  • In the abdomen, when abnormal cells collect in the liver or spleen
  • In the face and arms, when pressure on a vein called the superior vena cava causes blood to pool in the area
  • The lymph nodes, causing small lumps to form on the sides of the neck, in the underarms, or around the collarbone, where lymph nodes reside

Importantly, a child with swollen lymph nodes and no additional symptoms is more likely to have an infection than leukemia.

Also, tumors from other types of cancers are more likely to put pressure on the superior vena cava and lead to facial swelling. The swelling would be worse when a child wakes up, and it will improve throughout the day.

This is called superior vena cava syndrome and rarely occurs in cases of leukemia. However, it can be life threatening and requires emergency care.

Lack of appetite, stomachache, and weight loss

When Leukemia cells cause swelling in the liver, kidneys, or spleen, these organs can press against the stomach.

The result may be a feeling of fullness or discomfort, a lack of appetite, and subsequent weight loss.

Bone or joint pain

If a child seems to be in pain and complains that their bones or joints are sore or achy, this can indicate childhood leukemia.

When leukemia develops, the abnormal cells can collect close to the surface of the bones or inside joints.

In some cases, a child may also experience more obvious health problems.

These can include:


Anemia occurs when the body has a shortage of red blood cells.

Red blood cells are responsible for carrying oxygen around the body, and if someone is not producing enough, they may experience:

Coughing or breathing difficulties

Leukemia can affect parts of the body in and around the chest, such as some lymph nodes or the thymus, a gland located between the lungs.

If these parts of the body swell, they can put pressure on the trachea and make breathing difficult.

Breathing difficulties can also occur if leukemia cells build up in the lung’s small blood vessels.

If a child experiences difficulty breathing, seek emergency care.

Vomiting and seizures

If leukemia affects the brain or spinal cord, a child may experience:

  • weakness
  • seizures
  • vomiting
  • difficulty concentrating
  • issues with balance
  • blurred vision

Skin rashes

Leukemia cells that spread to the skin can lead to the appearance of small, dark, rash-like spots. Doctors call this collection of cells a chloroma or a granulocytic sarcoma, and it is very rare.

The bruising and bleeding that characterize leukemia can also cause tiny spots on the skin called petechiae to appear. These may also look like a rash.

The following are answers to common questions about childhood leukemia:

What is the most common age for childhood leukemia to occur?

Doctors most frequently diagnose childhood leukemia between the ages of 1–4. The median diagnosis is at 6 years of age.

Can leukemia show up suddenly?

The symptoms of acute leukemia often appear quickly, and they may be more noticeable. Commonly, a child will become ill with flu-like symptoms over just days or a few weeks. Children with chronic leukemia may have milder symptoms that develop gradually over time.

What are the types of leukemia?

There are two types of leukemia, and each can be chronic or acute. Acute types of leukemia are more common in children. They are:

Is there a cure for childhood leukemia?

While there is currently no cure, if a doctor diagnoses childhood leukemia early, the treatment success rate is high. The 5-year relative survival rate is 85.8%.

What causes childhood leukemia?

Researchers do not know the exact cause of childhood leukemia, but they believe the cause may be a combination of genetic and environmental factors. For example, some people’s inherited genes may predispose them to develop leukemia or make it more difficult for their body to process exposure to chemicals that can cause cancer.

There are different types of childhood leukemia. A child’s outlook will depend on the type and a range of other factors.

Regardless, diagnosing and treating leukemia early can improve the outcome. It is important for a parent or caregiver to discuss any concerns about a child’s health with a doctor as soon as possible.

Doctors can now treat many cases of childhood leukemia successfully. Methods of treatment are advancing and survival rates for some forms of the disease continue to improve.

Read this article in Spanish.