There are two broad types of infection; local and systemic (wide spread).

Local:

Local infections are contained to one spot such, like a skin infection due to an open wound. These are characterized by redness, warmth, swelling and/or tenderness at the site.

A wound can have fluid coming from it, that oftentimes is part of the healing process. It's not uncommon to have clear-ish (serous), bloody (sanguineous), or a combination of the two (serosanguineous) at an open wound.

However another sign of infection is when the drainage becomes "purulent." This is any color beyond those mentioned above- which can include yellow/green/brown drainage. Purulent drainage is often accompanied with a strong, foul smell. If it gets that bad over the counter (OTC) topical agents might not be enough to clean out the wound anymore and the person might need to go in for heavy duty antibiotics.

Another worsening sign is red streaks from the site moving towards the heart might be seen. The person/character is at risk of developing a blood infection which is approaching a medical emergency. At this point the body might also start to develop a systemic response to try and fight the infection.

Speaking of Systemic:

There are systemic responses and systemic infections.

Systemic reactions include fever, fatigue, malaise (basically feeling crappy), increased heart rate and/or blood pressure, nausea/vomiting, and diarrhea. These are commonly from bacteria or viruses.

Systemic infections impact a widespread area. One commonly known systemic infection is sepsis. Broadly stated sepsis is an infection in the blood.

Sepsis is crazy dangerous because the signs can start small and escalate quickly, leading to death. It's caused when the inflammatory response goes overload in the blood vessels. The vessels dilate which causes blood stasis (standing still) so the blood isn't transporting oxygen and nutrients to the cells. The blood abnormalities can cause bruising/ or petechiae (small red dots- see picture) on the skin.

Oftentimes sepsis goes hand in hand with DIC (disseminated intravascular coagulation) where all the clotting factors are used up in the blood. This means there's lots of clots in the bloodstream, while small cuts/microabrasions that actually need clots don't get the resources they need to close. The end result is a person risking/suffering from clots blocking important vessels and bleeding out internally at the same time. This can lead to a person going into (hypovolemic) shock*.

In the early stage a person might present with mild low blood pressure. The person will likely have an increase of respirations and a late stage sign is respiratory failure (usually there's no recovery once someone has reached that stage).**

There will be a decrease in urine production because the body is going to try and retain fluids (though this might only be seen in patients who are catheterized). Sometimes there's fever, but that varies from person to person.

The person will probably have "level of consciousness" (LOC) changes that might be presented as: delirium, restlessness, feelings of doom, anxiety.

Worst case scenario leads to death typically from multisystem organ failure d/t blood loss or clots.

Treatment:

For sepsis a person will need heavy duty antibiotics to treat the infection, they might need supplemental oxygen, since the person might be both bleeding and clotting the person might be on heparin (a blood thinner) to decrease the risk of a pulmonary embolism (blood clot in the lung) but since they're also bleeding the person will need high flow of IV fluids and/or blood transfusion. Medications that cause vasoconstriction (constriction of blood vessels) might also be used to keep fluid in the vascular system. (This is in no way an exhaustive list).

Key is the earlier the intervention the better the outcome for the individual.

*There will be a future chapter on shock/blood loss

**See chapter on Vital Signs for normal levels.