Chills, characterized by involuntary shivering and a sensation of cold, represent the body’s attempt to regulate its core temperature. This physiological response often precedes or accompanies a fever, signaling an underlying process. While chills can arise from various common conditions, their occurrence in individuals with cancer often carries heightened significance. They can be a concerning symptom, sometimes indicating the presence of infection or other complications that warrant prompt medical evaluation. Understanding the diverse origins of chills in cancer patients is important for appropriate management and care.
How Cancer Directly Triggers Chills
Cancer itself can directly induce chills through several biological mechanisms. As some tumors grow rapidly, parts of the tumor may outgrow their blood supply and undergo necrosis. This process releases inflammatory substances into the bloodstream, which can then trigger a systemic inflammatory response, leading to fever and associated chills.
Cancer cells, or the immune system’s reaction to them, can also release signaling proteins called cytokines. These cytokines signal the brain’s hypothalamus to raise the body’s temperature set point. The body responds by generating heat through shivering and vasoconstriction, experienced as chills, until the new, higher temperature is reached.
Cancers can also produce hormones or other active substances that cause systemic effects in distant parts of the body, a phenomenon known as paraneoplastic syndrome. These substances can sometimes interfere with temperature regulation, leading to symptoms like fever and chills. Certain blood cancers, such as leukemia and lymphoma, can specifically manifest chills as part of their symptom profile.
Infections in Cancer Patients
Cancer patients frequently experience chills due to their increased susceptibility to infections. Both the cancer itself and its treatments can significantly weaken the immune system, particularly by reducing the number of white blood cells known as neutrophils. This condition, called neutropenia, severely impairs the body’s ability to fight pathogens, making even minor infections potentially life-threatening.
Infections can originate from various sources, including bacteria, viruses, and fungi. Common entry points for these microbes include the skin, urinary tract, and respiratory system, or through medical devices like catheters. Once these pathogens enter the body, they provoke a strong inflammatory response.
This systemic inflammatory reaction involves the release of inflammatory mediators that reset the body’s internal thermostat to a higher temperature. The resulting physiological process to raise body temperature, which includes shivering and vasoconstriction, is perceived as chills. Cancer and its treatments can also damage natural protective barriers, such as the skin and mucous membranes, creating easy pathways for microorganisms to invade and cause infection.
Treatment-Related Causes of Chills
Cancer treatments can also directly or indirectly cause chills. Some chemotherapy drugs can induce infusion reactions that manifest as chills, fever, and flu-like symptoms shortly after administration. Chemotherapy frequently leads to neutropenia, significantly increasing the risk of infection, which then indirectly causes chills.
Immunotherapies, designed to stimulate the body’s immune system to fight cancer, can also trigger chills. This heightened immune activity can result in cytokine release syndrome (CRS), where a rapid and widespread release of inflammatory cytokines leads to fever and chills.
Other targeted therapies and biological agents may similarly cause fever and chills as side effects. Even localized radiation therapy can cause inflammation in the treated area, which may contribute to mild chills.