Leukemia and Fever: Understanding High Temperatures in Blood Cancer Patients

When it comes to leukemia, fever is a common and often concerning symptom. Patients frequently experience elevated body temperatures, typically ranging from 38°C (100.4°F), and in more severe cases, spiking to 39–40°C (102.2–104°F). These high fevers are not just random occurrences—they are closely linked to the underlying mechanisms of the disease and the body's compromised ability to fight infection.

Why Do Leukemia Patients Develop High Fevers?

Leukemia is a type of blood cancer that affects the production of white blood cells, particularly granulocytes. While patients may show an abnormally high count of white blood cells in blood tests, these cells are functionally defective. Unlike healthy white blood cells, which play a critical role in identifying and destroying harmful pathogens like bacteria and viruses, leukemic cells are unable to perform this essential immune function.

This malfunction leads to a severely weakened immune system. As a result, individuals with leukemia are far more susceptible to infections—even from normally harmless microorganisms. Because their bodies can't mount an effective defense, minor infections can quickly escalate into serious health threats.

Common Sources of Infection in Leukemia Patients

Infections often originate in areas of the body that are exposed to the external environment. The most vulnerable systems include the respiratory, gastrointestinal, and urinary tracts.

Respiratory Tract Infections

One of the most frequent complications is respiratory infection. Patients may develop persistent coughing, produce phlegm, and experience chest tightness or shortness of breath. These symptoms can rapidly progress, especially if treatment is delayed, leading to pneumonia or other severe lung conditions.

Gastrointestinal Infections

The digestive system is another common site for infection. Symptoms such as abdominal pain, diarrhea, and watery stools may indicate bacterial or viral gastroenteritis. In immunocompromised patients, these infections can lead to dehydration and require hospitalization.

Urinary Tract Infections (UTIs)

UTIs are also prevalent among leukemia patients. Signs include painful urination, urgency, and increased frequency of urination. If left untreated, the infection can spread to the kidneys, causing further complications.

Challenges in Managing Fever and Infection

Due to the impaired immune response, infections in leukemia patients are notoriously difficult to control. Fever tends to persist longer and reach higher peaks compared to individuals with healthy immune systems. Standard antibiotics may be less effective, and hospitalization is often required for intravenous treatment and close monitoring.

Moreover, distinguishing between a fever caused by active infection and one triggered by the leukemia itself (known as a "tumor fever") can be challenging for healthcare providers. This complexity underscores the importance of prompt medical evaluation whenever a leukemia patient develops a fever.

Key Takeaway for Patients and Caregivers

Fever in leukemia is more than just a symptom—it's a warning sign that demands immediate attention. Early detection and aggressive management of infections significantly improve outcomes. Patients undergoing treatment should monitor their temperature regularly and seek medical help at the first sign of fever, especially if it exceeds 38°C (100.4°F).