Skip to content
Back to glossary
Sleep & circadian

Glymphatic system

DEGlymphatisches System

The glymphatic system, described by Iliff, Nedergaard, and colleagues in 2012, is your brain's waste-clearance pathway. Cerebrospinal fluid flows along the spaces around blood vessels, swaps with the fluid between cells, and washes out metabolic waste, including beta-amyloid and tau. This clearance ramps up a lot during sleep (and under anesthesia in animals), when the space between brain cells widens by roughly 60% (Xie et al., 2013). When glymphatic clearance falters, it is implicated in Alzheimer's and other neurodegenerative diseases. That makes sleep a key point to protect your brain's longevity.

Last reviewed:

This definition is educational and is not medical advice, a diagnosis, or treatment. Talk to a doctor about any health decisions. Read our full medical disclaimer