What Causes a Fever? Here’s What to Know—And When to See a Doctor

FYI: A fever is actually a good sign that your body’s fighting off illness.

Encountering a fever can indeed give rise to a range of unpleasant sensations, a sense of unease, and an elevated state of concern, particularly given the current circumstances. It’s probable that you’ve experienced instances of heightened body temperature in the past, yet delving into the intricacies of what exactly triggers a fever might still remain somewhat elusive.

When faced with a persistent fever, it is undoubtedly prudent to seek the counsel of a medical professional. Nevertheless, it’s entirely human to harbor a curiosity about the underlying mechanisms driving this physiological response. This piece endeavors to unravel the intricate origins of fever while also offering valuable insights into the art of effectively managing this bodily phenomenon.

A fever, at its core, stands as a manifestation of the intricate interplay between your body’s immune system and potential external threats. It’s a remarkable indication of your body’s proactive defense mechanisms springing into action. The elevated temperature serves as a response to a perceived invader, be it a bacterial, viral, or fungal agent. This orchestrated response is guided by the immune system’s intricate dance, involving an array of cellular and biochemical processes aimed at thwarting the intrusion and restoring equilibrium.

Amid the complexity of the immune response, the hypothalamus emerges as a key player. Nestled within your brain, the hypothalamus serves as the control center, akin to an internal thermostat. When the immune system detects the presence of an unwelcome guest, it activates the hypothalamus, resulting in a series of events that culminate in raising your body’s temperature. This, in turn, triggers a cascade of coordinated actions, such as constriction of peripheral blood vessels, redirecting the blood flow towards vital organs, and reducing heat loss from the skin’s surface. All of these efforts contribute to creating an environment where the invading agents find it more difficult to thrive and propagate.

In the modern context, where health information is easily accessible, being armed with knowledge about the mechanisms underlying fever can alleviate some of the anxiety that can accompany this bodily response. This knowledge empowers you to better comprehend your body’s defense mechanisms and the active role you play in aiding its fight against potential invaders.

While a persistent fever warrants medical attention, there are certain strategies you can adopt to manage discomfort during the course of a fever. Maintaining hydration, for instance, remains paramount. Adequate fluid intake supports the body’s temperature regulation mechanisms and aids in preventing dehydration, a common concern during febrile episodes.

It’s noteworthy to highlight that a fever is often accompanied by other symptoms that can provide valuable insights into the potential cause of the fever itself. This intricate interplay of symptoms serves as a diagnostic clue for healthcare professionals, aiding them in identifying the root cause and determining the most appropriate course of action.

In the contemporary landscape, the emergence of the COVID-19 pandemic has brought about a paradigm shift in fever management. Given the potential association between fever and the virus, it’s crucial to exercise vigilance. If you find yourself facing a fever, especially in these times, seeking medical advice and potentially undergoing COVID-19 testing can be a pivotal step towards ensuring both your own health and the well-being of those around you.

In summation, while a fever can undoubtedly be a discomforting experience, it’s also a testament to the incredible intricacies of the human body’s defense mechanisms. By unraveling the complex orchestration of events that lead to fever, and by staying informed about its management strategies, you are better equipped to navigate this natural response with understanding and confidence.

What is a fever, again?

Fundamentally, a fever signifies a body temperature surpassing the norm. While a slightly heightened temperature might occur due to individual variation, the designation of fever is typically reserved for temperatures reaching at least 100.4 degrees Fahrenheit, as stipulated by the Centers for Disease Control and Prevention (CDC). The medical community has deliberated this, but the consensus leans toward the idea that a standard body temperature rests around 98.6 degrees, as noted by Kathryn Boling, MD, a primary care specialist at Mercy Medical Center in Baltimore.

What happens in your body when you have a fever?

Typically, a fever emerges as an indicator that your body is mobilizing its defenses against an ailment or infection, as elucidated by the US National Library of Medicine’s MedlinePlus.

The physiological processes underlying a fever can be intricate, yet in broad terms, it signifies the immune system’s active engagement and the concerted efforts of various bodily systems to safeguard vital organs, explains Roshi Gulati, MD, a family medicine practitioner at Northwestern Medicine Huntley Hospital.

When a fever manifests, your body’s hypothalamus—an intrinsic thermostat nestled within your brain—initiates a temperature elevation, clarifies Laura Miller, MD, MPH, a family medicine specialist affiliated with the University of Minnesota Medical School and University of Minnesota Physicians.

This initiation sets off a sequence of events, including constriction of blood vessels in peripheral areas, redirecting blood to essential organs, and curbing heat dissipation from the skin, notes Dr. Miller.

Rising body temperature can hinder bacterial growth, enhance the efficacy of white blood cells in defense, and prompt the generation of biochemical reinforcements, underscores Arindam Sarkar, MD, a primary care expert and assistant professor of family and community medicine at Baylor University. Essentially, a fever commonly signifies the body’s determination to repel invaders.

Under normal body temperature, most bacteria and viruses can persist without difficulty, according to Erik Blutinger, MD, an emergency medicine specialist at Mount Sinai Queens. However, the emergence of a fever might present a more challenging environment for their survival, he adds.

What usually causes a fever?

A diverse array of potential health concerns has the potential to trigger a fever, although they can generally be categorized into the subsequent groups, as outlined by Medline Plus:

1. Infections

2. Certain medications

3. Heat-related ailments

4. Cancers

5. Autoimmune disorders

6. Select childhood vaccinations

Nonetheless, infections, encompassing bacterial, fungal, and viral origins, tend to be the predominant culprits for fever, according to Dr. Gulati. Specifically, common cold viruses hold the primary position, and historically, people were advised to allow such viruses to run their course prior to the advent of COVID-19. These cold viruses often belong to the coronavirus family, with COVID-19 being notably more perilous compared to its counterparts.

Dr. Sarkar concurs, underscoring that viral and bacterial infections overwhelmingly account for the majority of fever cases. He adds, “Occasionally, prolonged and unexplained fever can stem from systemic rheumatic diseases and certain cancers.”

What should you do if you develop a fever?

Firstly, it’s crucial to bear in mind: “If you’re feeling relatively well, there might not be an immediate need to seek medication,” emphasizes David Cutler, MD, a family medicine practitioner at Providence Saint John’s Health Center in Santa Monica, California, in conversation with Health. However, if you’re experiencing discomfort or your fever is notably elevated, it could be beneficial to consider a fever-reducing remedy such as acetaminophen or ibuprofen, suggests Dr. Cutler. He also highlights the importance of maintaining hydration.

Additionally, paying attention to other accompanying symptoms is advised by Dr. Boling. This can offer valuable insights to your doctor regarding the potential underlying cause of your fever. Given that fever can serve as an indicator of COVID-19, it’s prudent to contact your healthcare provider for guidance on subsequent steps if you happen to develop one, notes Dr. Gulati. “The landscape of fever management has been significantly influenced by the emergence of COVID-19,” she states. “We now typically include COVID-19 testing alongside other diagnostic considerations when addressing a patient’s fever and related symptoms.”