Glymphatic System

The glymphatic system is an organ system in the central nervous system (CNS) designed to remove waste. Most of the body uses the lymphatic system to clear out waste, but the brain, which lacks important components of the lymphatic system, utilizes the glymphatic system instead.

The glymphatic system consists of astrocytes, which are star-shaped cells that act as channels for fluids to flow through. First, cerebrospinal fluid (CSF) enters the brain. It then mixes with interstitial fluid (ISF) and other brain solutes. This, combined with all the cellular waste it picks up along the way, will collectively exit through cerebral veins, which are typically involved in blood circulation within the brain.

Often, the glymphatic system is most active while people are sleeping, even more so during deep sleep. This is because the spacing between cells in the brain is much smaller while awake, so the fluid has less space to move through. If people don’t get adequate rest, the glymphatic system is not as efficient, which is why less sleep leads to decline in cognitive functions; there is waste in the brain that hasn’t been flushed out yet.

The waste the glymphatic system removes includes proteins that lead to brain diseases, like Alzheimer’s, or other forms of mental decline. Accumulation of waste can also lead to memory loss and sleep disorders. The glymphatic system was discovered fairly recently in 2012, and researchers continue to find more information about it and its connections with other aspects of the human body.

References:

Clinic, Cleveland. “Glymphatic System: What It Is, Function & How It Works.” Cleveland Clinic, 6 Oct. 2025, my.clevelandclinic.org/health/body/glymphatic-system.

Gao, Ying, et al. “Glymphatic System: An Emerging Therapeutic Approach for Neurological Disorders.” Frontiers in Molecular Neuroscience, vol. 16, 6 July 2023, https://doi.org/10.3389/fnmol.2023.1138769.

“Glymphatic System.” Wikipedia, 4 July 2022, en.wikipedia.org/wiki/Glymphatic_system.

Jessen, Nadia Aalling, et al. “The Glymphatic System: A Beginner’s Guide.” Neurochemical Research, vol. 40, no. 12, 7 May 2015, pp. 2583–2599, pmc.ncbi.nlm.nih.gov/articles/PMC4636982/, https://doi.org/10.1007/s11064-015-1581-6.

“Understanding the Glymphatic System.” Neuronline.sfn.org, neuronline.sfn.org/scientific-research/understanding-the-glymphatic-system.

Quiz: