Leukemia in Childhood: Signs, Causes and Care

Leukemia in childhood is a cancer of the blood-forming cells in the bone marrow. It can develop with symptoms such as unusual tiredness, frequent infections, easy bruising or bone pain, but these symptoms often have common non-cancer causes; a doctor can assess persistent or concerning changes.

Understanding leukemia in childhood

Leukemia in childhood is a cancer that starts in the bone marrow, the soft tissue inside bones that makes blood cells. In leukemia, immature abnormal white blood cells multiply more than they should. These cells can fill the marrow and reduce production of normal red blood cells, infection-fighting white blood cells and platelets, which help blood clot.

The two main forms are acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Acute leukemias usually develop and progress over weeks to months without treatment, so they require timely specialist assessment. Less commonly, children may develop chronic forms of leukemia, which tend to have different biological features and treatment plans.

Childhood leukemia is not contagious. It cannot be passed from one child to another through ordinary contact, shared food, school attendance or family life. Although a diagnosis can feel overwhelming, modern care is planned by pediatric cancer specialists and is based on the leukemia type, genetic features, the child’s age and response to treatment.

What are the first signs of leukemia in a child?

The first signs of leukemia in a child can be subtle and may resemble common childhood illnesses. They occur when the bone marrow cannot make enough healthy blood cells or when leukemia cells collect in tissues. No single symptom confirms leukemia, and most children with these symptoms do not have cancer.

Possible early signs include persistent tiredness, looking unusually pale, reduced energy for play, frequent or prolonged infections, fevers without a clear cause, easy bruising, nosebleeds, bleeding gums or tiny red-purple spots on the skin called petechiae. Some children develop bone or joint pain, particularly in the legs, or may limp or avoid walking because of discomfort.

Other possible symptoms include swollen lymph nodes, fullness or discomfort in the abdomen from an enlarged liver or spleen, reduced appetite, unexplained weight loss, headaches or shortness of breath. Symptoms that persist, recur often, worsen, or occur together deserve medical review. A clinician can consider common explanations such as viral infections, anemia or immune conditions while arranging tests if needed.

• Unusual fatigue or paleness may reflect low red blood cell levels.
• Repeated infections or fever can occur when normal white blood cell function is reduced.
• Bruising or bleeding may happen when platelet counts are low.
• Bone pain can arise when abnormal cells expand within the bone marrow.

Why are so many kids getting leukemia now?

It can seem as though more children are getting leukemia because families may hear about cases through social media, school communities and wider news coverage. However, leukemia remains uncommon in children. Changes in awareness, access to medical testing, cancer registration and reporting can also affect how often families encounter information about it.

For most childhood leukemia, there is no evidence that a recent everyday exposure, a specific food, routine activity, vaccination or parenting choice has caused the disease. Researchers continue to study why leukemia develops, including the complex changes in developing blood cells that can occur before birth or during childhood. These changes are usually not inherited from a parent.

It is understandable for families to look for a clear explanation after a diagnosis. In most cases, clinicians cannot identify one trigger. A pediatric oncology team can explain what is known about a child’s particular leukemia type and whether genetic counseling is appropriate, especially when there is a notable family history of cancer or a known inherited condition.

What triggers leukemia in children?

Childhood leukemia is usually caused by acquired genetic changes in blood-forming cells. “Acquired” means the changes develop in the cells during life and are generally not present in every cell of the child’s body. These changes can affect how cells grow, mature and respond to normal signals that control cell division.

In most children, no definite trigger is found. A small number of cases are associated with certain inherited genetic conditions, previous treatment with chemotherapy or radiation for another cancer, or very high exposure to ionizing radiation. These associations do not mean that every child with a risk factor will develop leukemia, and most children with leukemia have no recognized risk factor.

Parents should not blame themselves. Everyday bumps, ordinary infections, emotions, household routines, diet, mobile devices and school activities are not established causes of childhood leukemia. Families who have questions about a possible exposure should discuss them with the child’s doctor, who can place concerns in the appropriate medical context.

How long can a child have leukemia without knowing?

How long a child can have leukemia without knowing varies by leukemia type and by how quickly abnormal cells build up in the bone marrow. Acute leukemias commonly become noticeable over weeks to a few months, but early symptoms may be vague and can be mistaken for a viral illness, growth-related aches or fatigue from other causes.

Some children are diagnosed after symptoms become more obvious, while others have blood abnormalities found during testing for another reason. Chronic leukemias can sometimes develop more gradually and may be discovered through a routine blood test or an examination for nonspecific symptoms. It is not possible to determine the duration of leukemia from symptoms alone.

A delay in recognizing nonspecific symptoms is not necessarily anyone’s fault. The important step is to seek medical advice when a child’s health change is persistent, unexplained or worsening. A simple complete blood count can provide useful information about red cells, white cells and platelets, although further testing is needed to diagnose leukemia.

How doctors diagnose and classify childhood leukemia

A doctor begins with a detailed history and physical examination. They may ask about fever, infections, bruising, bleeding, pain, appetite, activity levels and family medical history. The examination can include checking for paleness, bruises, enlarged lymph nodes and changes in the abdomen.

Blood tests, especially a complete blood count and blood smear, are often the first investigations. Results may show low levels of healthy blood cells or abnormal cells in the bloodstream. Abnormal blood results do not always mean leukemia, but they may lead to urgent referral to a pediatric hematology-oncology team.

Confirming leukemia generally requires a bone marrow aspiration and biopsy. Specialists examine marrow cells and perform immunophenotyping, chromosome and gene tests to identify the exact subtype and features that guide treatment. Additional tests may assess whether leukemia cells are present in the fluid around the brain and spinal cord or in other areas. These results help the care team develop a personalized plan.

Treatment, support and follow-up

Treatment for leukemia in childhood is delivered by a specialized pediatric hematology-oncology team. Chemotherapy is a central treatment for many children. Depending on the leukemia subtype and risk features, care may also include targeted therapy, immunotherapy, radiation therapy in selected circumstances, or a stem cell transplant.

Treatment is usually given in phases and can last months or, for some forms of leukemia, longer. The team monitors blood counts, treatment response and side effects closely. Supportive care is equally important and may include medicines to prevent or treat infections, blood or platelet transfusions, nutrition support, pain management, emotional support and help with school and family routines.

Children and families should ask the care team about the goals of each phase, expected side effects, infection precautions and who to contact outside clinic hours. After treatment, follow-up visits monitor recovery, possible late effects and general development. Acıbadem Health Point’s multidisciplinary specialists and JCI-accredited hospitals provide diagnostic evaluation and treatment planning for international patients with childhood cancers.

When to seek medical care

A parent or caregiver should arrange prompt medical assessment if a child has unexplained bruising or bleeding, persistent pallor and tiredness, recurring fevers, frequent infections, ongoing bone pain, limping, swollen glands, abdominal swelling, or symptoms that are getting worse. These symptoms have many possible causes, but a clinician can decide whether blood tests or referral are needed.

Urgent medical care is needed if a child has difficulty breathing, severe weakness, confusion, a severe headache with vomiting, heavy bleeding, a high fever while appearing very unwell, or signs of dehydration. Emergency services should be used according to local guidance if the child appears seriously ill.

Parents do not need to wait for every possible symptom to appear. Trusting a concern about a child who seems noticeably different from their usual self is appropriate. Bringing a brief record of symptoms, dates, fevers, medications and any photographs of unexplained bruising or rash may help the medical visit.

Frequently asked questions