What's Really Going On When You're Sick with a Fever: A Sneak Peak Behind the Scenes

These past few days, I've been reminded of how lousy it feels to be acutely sick. Humbled by a tiny, adaptable virus wreaking havoc on my body, I've been pummeled by the flu. I don't get sick often. Sometimes, I think this experience is beneficial for me as a doctor. It raises my awareness of what my patients go through when they are in pain or ill. This helps me foster more empathy and compassion. So, my being sick this week isn't all bad.

But, I thought, dear reader, you might benefit from understanding what is going on behind the symptoms of fever, exhaustion, weakness, and chills. Suffice it to say—our body's immune response is magnificent, even inspiring! Here is a sneak peek into what your body is doing behind the scenes when you are ill with the flu (and other acute illnesses) and a few practical tips for better tolerating these symptoms without suppressing your immune system's wondrous work.

Understanding the Fever: What’s Happening?

When you spike a fever, it isn't the pathogen (in the case of the flu, the virus) directly causing it. A fever, also known as pyrexia, is "the elevation of an individual's core body temperature above a 'set point' regulated by the body's thermoregulatory center in the hypothalamus." (S. Balli, K. Shumway, S. Sharan from Physiology, Fever. NIH, National Library of Medicine). Typically, human body temperatures hover around 98.6°F (37°C), though there is some daily and feminine cycle variation of +/- 0.5°C. The key point here is that immune system cytokines and Prostaglandin 2 trigger the regulatory centers of the brain to raise the set point above what is typical. This renders advantages to the immune system.

Why is a Febrile State Beneficial?

Despite feeling awful with a fever, your immune system is stacking the deck in your body's favor against the pathogen.

Benefit 1: Enhanced Immune Response

A febrile state acts like a fire alarm, calling and activating various cells of the immune system for more active surveillance. Just like an alarm, these white blood cells (WBC) first responders literally move faster as they race towards the site of infection due to the slightly elevated body temperature. Additionally, some enzymes responsible for reproducing white blood cells speed up their chemical reactions in the body.

Benefit 2: Unfriendly Environment for Pathogens

The elevated core temperature creates a less hospitable environment for many microbes. They tend to grow best at normal body temperatures, which many have adapted to. This slows down their ability to reproduce.

Benefit 3: Iron Regulation

In response to a febrile state, many cytokines are released, including Interleukin-6. IL-6 triggers the liver to release Hepcidin, which regulates iron in the blood. Hepcidin responds by sequestering iron into its storage form, Ferritin, in the liver. This is crucial because many pathogens feed on iron as a source of fuel. With less fuel, the pathogen's reproduction is further stifled.

Benefit 4: Energy Diversion

A fever suppresses appetite. Metabolically speaking, digestion demands extra energy. By suppressing appetite and intake, the body diverts energy to the heightened immune response.

Benefit 5: Metabolic Shift

A febrile state is metabolically demanding. A mere 1°C elevation can increase the metabolic rate by 10-12%. The body's metabolism switches from utilizing glucose as fuel to breaking down proteins and fats, which have a higher caloric density. This is helpful energetically and reduces the amount of glucose available to the pathogen. Glucose is an excellent medium for bacterial growth and can blunt the immune system's ability to respond.

Benefit 6: Encouragement to Rest

A fever forces the individual to slow down and rest. During rest and sleep, the immune system increases the number of Cytokines and White Blood Cells—specifically T-Cells that promote the activation and proliferation of other vital immune cells, helping the body eliminate the pathogen.

Father with sick child.

Tips for Weathering A Fever Naturally

Rather than instantly reaching for acetaminophen to suppress the body's natural response to fever, here are a few things to try instead:

Tip 1: Stop. Rest. Sleep. Go to Bed.

It is surprising how many of us ignore or suppress our body's cues designed to help us heal from acute infection. If you feel tired or exhausted, listen to your body and lie down. Ignoring these cues when you are becoming acutely ill enables the pathogen to gain the upper hand in the battle with your immune system and can prolong the battle itself.

Tip 2: Hydrate. Push the Fluids.

Listen to your thirst and keep a water bottle beside the bed to remind yourself to drink often. Craving ice-cold water? Use an insulated water bottle with ice to keep it appealing. Craving a warmer liquid when you have chills? Try an herbal immune support tea or veggie broth. Add a Vitamin C packet with electrolytes to your water to help your immune system and ward off dehydration.

Tip 3: Fast from Foods.

Do not worry if you have a fever and lack appetite. This is normal and even helpful for the immune system's energy diversion demands. Most of us have plenty of stored fat that can be broken down for energy.

Tip 4: Use a Cold Wet Washcloth.

Feeling uncomfortable hotness on your head during a fever? A cool wet washcloth can provide soothing relief and comfort.

Tip 5: Avoid All Sources of Sugar Intake.

Sugar blunts the immune response and stimulates the growth of numerous pathogens. Avoiding sugar intake deprives the pathogen of this growth opportunity and further supports the immune response.

Tip 6: Unplug from Your Phone/Social Media.

An acute illness can be an opportunity to take a break from the everyday online stressors we regularly encounter. Seize the chance to unplug. You won't regret it.

Tip 7: Pay Attention to the Details of Your Fever.

If you intend to seek naturopathic/homeopathic support for your acute illness, pay attention to the specifics of your fever. These nuances are often important for a personalized homeopathic prescription. Consider where the chill begins in your body. Do you perspire with the fever? If so, which parts of your body sweat? Are you thirsty with the fever? For what temperature of water? In which phase of the fever? All these details will help guide the prescriber in finding a remedy that works with your body rather than against its efforts to heal you.

When to Seek Treatment

Most of the time, fevers (especially low or medium-grade ones) are a natural and even positive part of the immune system's response to a pathogen. However, there are situations where the situation becomes dangerous, and professional treatment is necessary. Here are a few concerning signs to watch for:

1. Hyperthermia: Defined as a temperature above 41°C or 105.8°F, it is distinct from a febrile state. The rise in the body's core temperature exceeds the set point temperature and regulation of the hypothalamus. This typically happens due to severe overheating, such as in heat exhaustion or heat stroke, usually caused by overexertion and dehydration in a hot environment.

   
   

2. Delirium, Convulsions, or Coma: These symptoms, especially when combined with a temperature above 104°F, hot, red, dry skin, and tachycardia, can be life-threatening. Taken together, these are usually signs of heat exhaustion or heat stroke.

   
   

3. Persistent, Non-Responsive Fevers: When a fever continues persistently without responding to anti-pyretics for a length of time, it can signal something more serious, such as malignancy or sepsis, especially in a hospital setting. Therefore, seek help in this situation.

   
   

4. Febrile Seizures: These usually occur when the change in temperature increases too quickly for the body to adapt, triggering convulsions. The main concern in a febrile seizure is the deprivation of oxygen to the brain.

   
   

In general, pay greater attention to the higher the temperature. Rest. Take your temperature more frequently and watch out for dehydration. Push yourself to drink plenty of fluids. Most of the time, fever can be a powerful tool of the immune system that induces healing and helps wipe out the pathogen. Learning to lean in and trust the wisdom of the body during fever can be a powerful addition to your acute healing repertoire.