What is the percentage of water present in our brain?

The human brain is one of the most vital and complex organs in the body, responsible for controlling thought, memory, sensation, and movement. A significant feature of the brain is its high water content, which makes up approximately 85% of its total mass. Water is essential for the brain to function properly because it plays a key role in maintaining cell structure, electrical activity, and nutrient transport.

The brain consists of billions of neurons and supporting cells called glial cells. Water is critical for neurons to transmit electrical impulses effectively. It helps maintain the ionic balance required for proper nerve signal conduction. Additionally, water in the brain is a major component of cerebrospinal fluid (CSF), which cushions the brain, removes metabolic waste, and provides a stable chemical environment for neurons.

A decrease in the brain's water content, due to dehydration, can affect cognitive functions, causing confusion, poor concentration, and headaches. Conversely, proper hydration helps maintain mental performance, memory retention, and overall brain health. This high water percentage is a fundamental reason why maintaining adequate hydration is essential for both children and adults.

Understanding the brain’s water composition is important in biology and human physiology because it highlights the relationship between cellular function, hydration, and neurological health. The fact that water constitutes about 85% of the brain demonstrates how delicate and dependent the nervous system is on maintaining proper fluid balance.

This concept also provides a foundation for further studies in neuroscience, physiology, and health sciences, emphasizing how a simple substance like water is critical for sustaining one of the body’s most complex organs.