A fever represents an elevated body temperature, serving as a symptom indicating an underlying condition rather than a disease itself. One cannot directly “catch” a fever from another person, but rather the infection or illness that prompts the body’s immune system to generate a febrile response.
Understanding What a Fever Is
A fever is the body’s natural physiological response to combat infection or inflammation, signaling that the immune system is actively working. This process begins when foreign substances like bacteria or viruses enter the body. These pyrogens stimulate immune cells to release endogenous pyrogens.
These endogenous pyrogens travel through the bloodstream to the hypothalamus, a region in the brain that regulates body temperature. Upon receiving these signals, the hypothalamus raises the body’s temperature set point to a higher level. To reach this new, elevated set point, the body initiates mechanisms such as shivering to generate heat and vasoconstriction to conserve it, causing the body temperature to rise. This elevated temperature can inhibit the multiplication of pathogens, aiding the immune system in its fight.
How Illnesses That Cause Fevers Spread
Contagious illnesses that commonly result in fevers are transmitted through various mechanisms. Direct contact involves physical interaction such as skin-to-skin contact, kissing, or sexual intercourse. This close proximity allows for the exchange of bodily fluids or direct transfer of microbes.
Another common mode is droplet transmission, where respiratory droplets containing infectious agents are expelled during actions like coughing, sneezing, or even talking. These droplets travel short distances before settling, and can be inhaled by someone nearby or land on their mucous membranes. Airborne transmission involves much smaller particles, which can remain suspended in the air for extended periods and travel longer distances, potentially infecting individuals who enter the space even after the infected person has left.
Indirect contact involves the transfer of pathogens via contaminated surfaces or objects. When an infected person touches a surface, they can leave behind germs, which can then be picked up by another person who touches the same surface and subsequently touches their eyes, nose, or mouth. This highlights the importance of hand hygiene in preventing the spread of these illnesses.
Common Illnesses Associated with Fever
Many common contagious illnesses often present with a fever. Influenza, commonly known as the flu, is a respiratory infection caused by viruses that causes fever, along with symptoms like cough, sore throat, and body aches. It spreads primarily through respiratory droplets released when an infected person coughs or sneezes.
The common cold can also cause a fever and is caused by various viruses. Like the flu, it spreads through airborne droplets and direct contact. Bacterial infections such as strep throat, caused by Streptococcus bacteria, lead to a sore throat and fever, and are transmitted through close contact or respiratory droplets. Chickenpox, a highly contagious viral illness, is characterized by a distinctive rash and fever, spreading through direct contact and airborne transmission of the virus. These examples underscore that it is the contagious illness, rather than the fever itself, that is transmitted between individuals.