Drinking is the act of consuming a liquid through the mouth. Water, for example, is required for many of life's physiological processes, and excess or decreased water intake is associated with health problems.
The sensation caused by dehydration of the body is called "thirst". The sensation of thirst is a dry feeling in the back of the throat and an intense desire to drink fluids. Thirst is regulated by the hypothalamus in response to subtle changes in the body's electrolyte levels, and also as a result of changes in the volume of blood circulating.
Much of the world's disease is caused by the lack of clean drinking water. Lack of water in diet will eventually cause death by hypernatremia and dehydration, particularly when sweating consumes much of the body water. Unclean and unsanitary water can contain many bacteria and parasites that would otherwise be absent in clean water. Studies show that in some developing countries more than half of the population does not have access to safe drinking water.
It is also possible to overhydrate, which sometimes happens with athletes who consume too much water, thereby diluting the concentration of salts in the body. Also the consumption of alcohol can lead to excessive consumption of water due to the fact that alcohol dehydrates the body. Overconsumption of water can be a sign of disease and/or mental health problems(e.g. damage to the hypothalamus), as stated above.
Drinking vessels may include glasses, cups, bottles, canteens, and bowls.
Fewer skills are required for drinking from a baby bottle or a cup that has a lid with a nozzle. Therefore, these are useful for small children and people with some disabilities. If neither eating nor drinking are possible, some alternatives are enteral nutrition and parenteral nutrition.
"Drinking" is also used as a synonym for the consumption of alcoholic beverages. Additionally, having "thirst" or being "thirsty" can metonymically express a desire for alcohol.