20/01/2026
Spinal discs need water to stay plump, flexible, and act as shock absorbers; they are largely water-filled, and hydration allows them to absorb nutrients, cushion impacts, and maintain height, while dehydration makes them stiff, thin, and prone to injury and pain, as water is squeezed out by daily pressure and reabsorbed during rest.
Why discs need water
Shock absorption: Water provides the internal pressure (turgor) that keeps discs firm and allows them to effectively cushion the vertebrae from movement.
Flexibility & movement: Hydrated discs are supple and flexible, allowing for bending and twisting; dehydration makes them brittle and less resilient.
Nutrient delivery: Water helps discs absorb nutrients and oxygen and expel waste, a process vital for their health.
Disc height: Water maintains the disc's height, ensuring proper spacing between vertebrae; dehydration causes thinning and potential misalignment.
What happens when discs are dehydrated
Disc desiccation: Loss of fluid, making discs dry and brittle, like a dried-out rubber band.
Increased injury risk: Dehydrated discs absorb shock poorly, increasing vulnerability to bulging or herniation.
Pain & misalignment: Thinning discs can cause vertebrae to shift, leading to pressure, misalignment, and back pain.
How hydration works (the pumping mechanism)
Pressure squeezes water out: Daily activities like walking, sitting, and bending compress the discs, forcing some water out.
Rest allows rehydration: During rest or sleep, the pressure lessens, and the discs reabsorb water and nutrients, rehydrating and regaining height.
Hydration supports this cycle: Drinking enough water ensures there's fluid available for the discs to draw from during rest.
