What percentage of blood is composed of water?

The correct percentage of water in blood is approximately 90%. Blood is a complex fluid that consists of various components, including red blood cells, white blood cells, platelets, and plasma. Plasma, which makes up about 55% of total blood volume, is predominantly composed of water, accounting for around 90% of its volume. This high water content is crucial for maintaining blood viscosity, transporting nutrients and waste products, and regulating body temperature. Understanding the composition of blood and its water content is vital in fields like esthetics and healthcare, as it highlights the importance of hydration for overall skin and body health.