What Does Drinking Water Do for the Body?

More than two-thirds of the human body, by weight, is water, and water is essential to the function of the cells, tissues and organs in the body. According to the World Health Organisation (WHO), access to safe drinking water is a health issue at national, regional and local levels.

Bodily Functions

• Water forms the base of saliva and serves to lubricate the alimentary canal -- the digestive system -- so that food and waste move easily through the body. It also regulates metabolism and body temperature -- evaporative heat loss through sweating, for example -- and maintains brain and skeletal muscle function at a high level.

Disease Prevention

• According to industry experts, drinking the recommended eight glasses of water a day can reduce incidence of many diseases and ailments, including diabetes, depression and bladder, breast and colon cancers.

Lack of Water

• Even mild dehydration -- which can result from just a 2 percent fall in the body’s water content -- can lead to fatigue and reduced brain function, according to the WHO.