Why are you a little taller in the morning?
The discs between your spinal bones slowly change height throughout the day.
A spine built to carry weight
Your vertebrae are separated by intervertebral discs that distribute loads and allow movement. These discs contain water-rich tissues, and their shape changes slightly under pressure. During a day of standing, walking and sitting, the spine carries repeated loads that squeeze some fluid out of the discs.
What happens during sleep
When you lie down and reduce the pressure along your spine, the discs gradually rehydrate and regain some height. That makes many adults a little taller after a night of rest than they are late in the day. The difference is normal and is not the same as permanent changes in skeletal height.
A reminder that anatomy is dynamic
Bones provide structure, but the tissues between them are flexible and responsive to everyday forces. Hydration, posture, movement and how measurements are taken can influence small changes in height. It is a good example of how a simple observation—the morning height advantage—reflects ongoing mechanical and biological processes.
External references are provided for exploration; Curio Hour’s explanation is written separately.