Sodium regulates mental and physical performance by controlling fluid balance, blood pressure, and neuronal function—but optimal intake varies by activity level, stress, and blood pressure status. Learn how to determine your ideal salt intake using the Galpin Equation and understand why the brain's salt-sensing neurons influence thirst, appetite, and stress resilience. The OVLT brain region detects sodium levels and triggers vasopressin release to regulate urine production and fluid retention, maintaining blood and brain health. People with low blood pressure or orthostatic disorders may benefit from 6–10 grams of daily salt, while those with hypertension should limit intake to 2.3 grams per day.