Thirst is regulated by both intracellular and extracellular mechanisms within the body. Intracellular thirst is triggered by a lack of fluids inside cells, while extracellular thirst responds to a lack of fluids outside cells. Together these mechanisms normally work to maintain fluid balance and trigger thirst when drinking is required to restore normal fluid levels.

1. Normal thirst mechanisms

2. Intracellular thirst.

3. Extracellular thirst

4. Normal thirst comprising both in

5. Normal thirst mechanisms with minimal drinking.