The glymphatic system is a newly discovered waste clearance system in the central nervous system (CNS) that utilizes perivascular channels formed by astrocytes to efficiently remove soluble proteins and metabolites. It functions mainly during sleep and is largely inactive during wakefulness, suggesting that sleep is essential for eliminating potentially neurotoxic waste, including β-amyloid. The system also helps distribute non-waste compounds like glucose, lipids, and neurotransmitters. Recent studies indicate that glymphatic function is impaired in various diseases, potentially contributing to neurodegenerative disorders, traumatic brain injury, and stroke. CSF production occurs primarily in the choroid plexus, where ions like Na+, K+, and HCO3- are transported across epithelial cells to generate an osmotic gradient that drives water movement. Key transporters such as Na+/K+-ATPase and NCBE are essential for this process. CSF is produced in the choroid plexus and drains into the peripheral lymphatic system via the olfactory bulb and cranial/spinal nerves. The role of the choroid plexus in CSF production is debated, with some proposing that CSF formation occurs through filtration and flux through capillary walls. The brain's vasculature is unique, with perivascular spaces, such as the Virchow-Robin space, facilitating CSF and interstitial fluid (ISF) exchange. These spaces are surrounded by astrocytic endfeet and are crucial for waste clearance. The glymphatic system, which resembles the lymphatic system, involves CSF movement along periarterial spaces, facilitated by AQP4 channels in astrocytes. This system is active during sleep and is suppressed during wakefulness, with sleep promoting efficient clearance of waste products. Glymphatic function is regulated by factors such as norepinephrine, which suppresses the system during wakefulness. Aging significantly reduces glymphatic activity, contributing to the accumulation of misfolded proteins like β-amyloid. Traumatic brain injury impairs glymphatic function, leading to the accumulation of debris and exacerbating injury. The glymphatic system also plays a role in transporting biomarkers of brain injury, such as GFAP and S100B, into the bloodstream. Recent studies have shown that the glymphatic system is crucial for clearing metabolic waste and transporting nutrients and drugs. Future research aims to develop diagnostic tools to assess glymphatic function, which could improve the understanding and treatment of neurodegenerative diseases. MRI and intrathecal lumbar injections are promising methods for visualizing glymphatic function in humans. The glymphatic system's role in distributing substances like lipids, glucose, and drugs highlights its importance in brain homeostasis and disease management.The glymphatic system is a newly discovered waste clearance system in the central nervous system (CNS) that utilizes perivascular channels formed by astrocytes to efficiently remove soluble proteins and metabolites. It functions mainly during sleep and is largely inactive during wakefulness, suggesting that sleep is essential for eliminating potentially neurotoxic waste, including β-amyloid. The system also helps distribute non-waste compounds like glucose, lipids, and neurotransmitters. Recent studies indicate that glymphatic function is impaired in various diseases, potentially contributing to neurodegenerative disorders, traumatic brain injury, and stroke. CSF production occurs primarily in the choroid plexus, where ions like Na+, K+, and HCO3- are transported across epithelial cells to generate an osmotic gradient that drives water movement. Key transporters such as Na+/K+-ATPase and NCBE are essential for this process. CSF is produced in the choroid plexus and drains into the peripheral lymphatic system via the olfactory bulb and cranial/spinal nerves. The role of the choroid plexus in CSF production is debated, with some proposing that CSF formation occurs through filtration and flux through capillary walls. The brain's vasculature is unique, with perivascular spaces, such as the Virchow-Robin space, facilitating CSF and interstitial fluid (ISF) exchange. These spaces are surrounded by astrocytic endfeet and are crucial for waste clearance. The glymphatic system, which resembles the lymphatic system, involves CSF movement along periarterial spaces, facilitated by AQP4 channels in astrocytes. This system is active during sleep and is suppressed during wakefulness, with sleep promoting efficient clearance of waste products. Glymphatic function is regulated by factors such as norepinephrine, which suppresses the system during wakefulness. Aging significantly reduces glymphatic activity, contributing to the accumulation of misfolded proteins like β-amyloid. Traumatic brain injury impairs glymphatic function, leading to the accumulation of debris and exacerbating injury. The glymphatic system also plays a role in transporting biomarkers of brain injury, such as GFAP and S100B, into the bloodstream. Recent studies have shown that the glymphatic system is crucial for clearing metabolic waste and transporting nutrients and drugs. Future research aims to develop diagnostic tools to assess glymphatic function, which could improve the understanding and treatment of neurodegenerative diseases. MRI and intrathecal lumbar injections are promising methods for visualizing glymphatic function in humans. The glymphatic system's role in distributing substances like lipids, glucose, and drugs highlights its importance in brain homeostasis and disease management.