An infection occurs when a foreign species colonizes in the body of a host organism, and the host is unable to ward it off. The foreign organism, or pathogen, attempts to benefit from the host by using its available resources to multiply; the host will typically experience harmful side effects during this process of colonization as the pathogen impedes its ability to function properly and fend off the infection. During the onset of infection, the host’s reaction to infection is characterized by inflammation. This can lead to chronic wounds, gangrene, loss of limb, and in severe cases, death.

A pathogen is broadly defined as a microscopic organism, but it can also include:

  • Feces
  • Parasites
  • Fungi
  • Viruses
  • Prions
  • Viroids

A relationship between a parasite and host in which the parasite reaps the rewards of symbiosis while causing harm to the host is called parasitism. The segment of the medical profession that concentrates on infections and pathogens is known as infectious disease.

A secondary infection is one that emerges in the midst of or after treatment of an existing primary infection. An occult infection is a hidden infection in which the host does now show any symptoms.

There are two general categories of infection: local and systemic. Each cause symptoms that are both similar and unique.

A systemic infection is normally the result of the invasion of bacteria or virus. Since it targets the bloodstream, the host will exhibit symptoms throughout their whole body. Common examples of systemic infection include colds, viruses, flu, mononucleosis, and strep throat. Someone who has contracted this sort of infection will likely experience:

  • Fever
  • Achiness
  • Chills
  • Upset stomach
  • Vomiting
  • Loss of strength

A local infection does not manifest itself through the entire body of the host–just a certain area. For instance, an open wound that becomes infected would be considered a local infection. Symptoms occur right at the site of the infection and may include:

  • Soreness
  • Reddish skin tone
  • Pus
  • Inflammation
  • Secretions with foul odor
  • Warmer than surrounding uninfected areas
  • Fever (lone systemic symptom that a local infection may cause)

Nonprescription treatment that works to lower fevers and reduce pain includes Tylenol, ibuprofen, or aspirin. If you have a local infection, make sure the region is always kept clean. You may apply warm, damp cloths to it as well. If the symptoms become too severe (e.g., fever gets too high, wound refuses to heal properly), always consult a doctor. They can provide you with the correct diagnosis along with a prescription to get you back on the path to better health.