Which is NOT one of the five symptoms of inflammation?

The presence of headache is not considered one of the five classic symptoms of inflammation. The five classic symptoms of inflammation are heat, redness, swelling, pain, and loss of function.

Heat refers to increased temperature in the affected area, which occurs as a result of increased blood flow. Redness is also due to increased blood flow, causing the blood vessels to dilate and fill with more blood. Loss of function can occur as a result of swelling and pain affecting the ability to use the affected body part normally.

Headaches can be a result of inflammation in different contexts, such as when there is systemic inflammation or inflammation affecting the head, but it is not a direct indicator of localized inflammation like the other four symptoms mentioned. Therefore, headache does not fit into the classic symptomatology associated with inflammation.