Medicine 101: The Science Behind a Fever

The unbearable warmth, the chills, the nausea, the aches — everyone has experienced the dreaded symptoms of fever at least once in life. Fevers come in all shapes and sizes and affect bodies in different ways. For example, you might be able to carry on life but feel slightly terrible for a full week or more. Or, you might be fully bed-ridden for 24 hours, but the next morning you wake up ready to conquer any obstacle. The reason fevers vary is because fever is one of your body’s defenses against disease, and different diseases will cause your body to react in different ways. While you can (and should!) stock up on some over-the-counter pain and fever relievers in case an unexpected illness sneaks up on you, it also helps to learn about the common causes of fever and what the symptoms are doing to help heal your body.

What Is It?

Fever is also known in the medical world by the terms . All of these terms serve to describe the state when your body is intentionally raising its internal temperatures above the normal range, which for typical humans is between 98 and 100 degrees Fahrenheit. Body temperatures will fluctuate naturally throughout the day in response to activities like eating, sleeping, and working out. However, fevers see internal temperatures rising much higher much faster than these activities, and fevers usually signal an immune response. A region in the brain called the hypothalamus is tasked with regulating the body’s temperature. When the immune system determines that the body is under attack (due to virus, bacteria, or some other infection), the hypothalamus sets into motion the symptoms of a fever. Blood vessels constrict to prevent the release of heat, muscles tense, and various hormones are released, like epinephrine and adrenaline. These body responses are the main causes of fever’s extensive list of symptoms. A rising internal temperature will make a person shiver and feel chills, until the temperature begins to level off, at which point the uncomfortable heat will set in. Eventually, the person will feel muscle pain all over the body due to his or her constricted muscles, and the wealth of hormones can cause other unpleasant symptoms, like a racing heart, an upset stomach, and headaches. When a fever breaks — or when the body’s temperature begins to decline again — the body will attempt to cool off faster, which means the sweating will start; however, this means the worst of the fever is over, and a person can start looking forward to feeling better.

What Causes It?

Because , the body only initiates this rise in body temperature when it believes it is under attack. Here are some common reasons the immune system might sense a threat and start a fever:

• Infections. These can come in many forms, including influenza (the flu), HIV, malaria, and even the common cold.
• Medications. Adverse reactions, side effects, or withdrawal may spurn the body to create a fever. “Drug fevers” are usually from antibiotics, antihistamines, and narcotics.
• Traumas. When your body experiences extreme stress, the body may react inappropriately with a fever. Heart attacks, strokes, surgery, or even experiences like excessive hemorrhage, burns, or heat can increase internal temperature.

What Should Cause Worry?

Most physicians will tell you that minor fevers are beneficial, and though symptoms may be uncomfortable, they should abate soon and are no cause for worry. However, there are a few situations when fever sufferers should seek prompt medical attention. Pyrexia constitutes temperatures between 98 and 106 degrees Fahrenheit, but if an internal temperature breaches 106 degrees Fahrenheit (41 degrees Celsius) a person begins experiencing . Temperatures this high will cause significant damage to delicate body symptoms. Most frequently, unaddressed hyperpyrexia will lead to excessive bleeding and organ failure. The most effective management technique yet discovered is immediate and aggressive cooling measures. Prolonged fever — meaning one that lasts longer than about 10 days — could harm the body irreparably as well. Even if you are experiencing what is typically a low-grade fever (between 101 and 104 degrees Fahrenheit) for a longer duration, your body can’t handle these temperatures for so long, and your systems will start to fail. In many cases, this dangerously high fever is a symptom of a serious underlying cause, like cranial bleeding, dramatic infections, or even cancers. If you experience a fever of this kind, it is imperative to seek medical attention straight away, or you risk complications of a high fever as well as those of the primary disease. Fevers are a natural part of human life. Though they may be a dreadful state, fever actually works to heal your body by killing any invading infection. While it is natural and healthy to succumb to pain and fever relievers during your difficult time, you can also thank your body for its intelligent and quick response to deadly disease.