Why a Fever is a Good Thing


Fever is the natural body’s response to fighting infection and does not, in itself, can harm. Fevers are signs of some sort of illness or infection. Not all fever is from an infectious source. Keep a broad differential diagnosis. Infections cause most fevers.

Fever is the result of your immune system’s response to a foreign invader. These foreign invaders include viruses, bacteria, fungi, drugs or other toxins. A fever is usually a sign that your body is working to keep you healthy from an infection.

The Causes of a Fever

Infectious causes of fever include urinary tract infection, pneumonia, meningitis, intra-abdominal, skin/soft tissue, and osteomyelitis. Fever (pyrexia) is the most common presentation of infection. A part of the brain called the hypothalamus controls your body temperature. In response to an infection, illness or some other cause, the hypothalamus may reset the temperature to a higher level.

The differential diagnosis of fever is broad and not limited to infectious etiologies. One cannot say that every patient with infection has fever.

The First Line Tests for a Fever

The preliminary investigation should include a complete blood count, liver function test, ESR (sedimentation rate), urinalysis and basic cultures. Urinalysis, urine culture and chest x-ray, usually already done, are repeated only if the findings indicate that they should be. It may still be unclear after a few hours as to whether the source of the patient’s fever is infectious, even after a robust use of ancillary testing.

Analysis of the urine may show signs of urinary tract infection. Specifically, the presence of nitrate and white blood cells. In the sickest patient cohort, e.g., shock, empiric antibiotics are clearly indicated when sepsis is high on the differential diagnosis.

Duration of fever affects the likelihood of a positive urinalysis. The yield of urinalysis increased significantly in patients with a fever of 3 days or longer duration. The most common pathogens that cause urinary tract infection are enteric microbes, but mainly E-coli (which account for 70-90% of simple cases).

Beware of the Danger of a Urinary Tract Infection

Urinary tract infection is a common infection. Upper track urinary tract infections affect the kidneys. These can be potentially life threatening if bacteria move from the infected kidney into the blood. This condition, called sepsis, can cause dangerously low blood pressure, shock and death.

Women are more likely to get urinary tract infection than men. About 60% of women and 12% of men will have at least one urinary tract infection in their lifetime.

Left untreated, infections of the lower urinary tract can spread to the kidneys and may cause permanent kidney damage. Relevant history includes a previous urinary tract infection, kidney stones, kidney disease. Structural abnormalities provide shelter for bacteria. These structural abnormalities may include renal stones, catheters, and polycystic kidney disease.

Infection in the upper urinary tract generally affects the kidneys (pyelonephritis), which can cause fever, chills, nausea, vomiting and other severe symptoms. A kidney infection is, in essence, a urinary tract infection that has spread into the kidneys. While this type of infection is rare, it’s also very dangerous.