Body water is a proportion that varies
On average, water makes up about 60% of an adult’s body mass, but the figure varies substantially, including with age and body composition. Water provides the medium for many chemical reactions, forms part of blood and tissues, and supports thermoregulation and cell function.
Illustration is AI-generated and conceptual, not a medical diagram or advice.
Substantial fluid loss can cause severe dehydration, circulatory problems, and life-threatening conditions. However, “losing 10% of body water” is an ambiguous threshold: the percentage may refer to total body mass or to the body’s water stores, and effects depend on circumstances and health. Severe dehydration needs urgent medical assessment; do not wait for a particular percentage of loss.