Signs

Objective: Understand how the body maintains balance (homeostasis) and what happens when disruptions occur, leading to disease.
Homeostasis goal: restore normal set points for key variables (e.g., blood pressure, blood glucose, body temperature) to keep the body in a healthy state.
When disruptions cannot be corrected by the body's systems due to pathological processes, the state can be described as a disease.
Three introductory terms introduced in this objective: signs, symptoms, and syndromes.

Definition: objective, observable, and measurable variables. These are things that can be seen, counted, or quantified.
Criteria: is it observable or measurable? Can you see it, measure it with a device, or count it?
Examples:
- Pale skin: observable visually; descriptive and objective.
- Fainting: observable (can count occurrences over a period).
- Sweating: observable visually.
- Fever: measured value (temperature); when the measurement crosses a threshold, e.g., approaching or exceeding fever range.
- Irregular heartbeat: measurable via heart rate; rhythm checked with ECG/EKG.
- ECG/EKG: graphical measure of heart’s electrical activity; used to observe rhythm and compare to normal.
- Diarrhea and vomiting: observable events in a patient’s behavior and bodily output.
- Seizures: visible episodes that can be timed and counted.