When any part of the body is exposed to the potential for infection by a pathogen a rapid, non-specific inflammatory response occurs. Inflammation occurs when the skin is broken or when internal organs react to chemicals and pathogens. The inflammation aids in prevening further damage to organ(s) or tissues around the area. After the area has been made source for infection, histamine is released which increased blood flow to the area as shown in step 'a' in the diagram below. This is done by histamine making the capillaries more susceptible to leakage (step b). This causes the area to feel warm and swollen(step d). Blood supply rushes to the source of inflammation in order to aid with the repair of the damaged site and also to promote white blood cells rushing to the area to destroy foreign pathogens (step c). This is shown in the diagram below; with the splinter piercing the body, damaged cells release chemical alarm cells, this causes more fluid that normal to leak out of the capillaries, white blood cells move to the area and attack invading temperature and then the temperature increased in order to prevent bacteria growing in the exposed area.
Inflammation can be characterized by 4 symptoms: pain, redness, heat and swelling; all of which are caused by a rush of cells to the area, coupled with sensitive nerve cells which are located near the source of many areas become inflamed.Another possible symptom is loss of functions due to increased pressure.