Water may also help with weight loss, if it is consumed instead of sweetened juices and sodas. “Preloading” with water before meals can help prevent overeating by creating a sense of fullness.

Cartilage, found in joints and the disks of the spine, contains around 80 percent water. Long-term dehydration can reduce the joints’ shock-absorbing ability, leading to joint pain.

Up to 65% of the human adult body is water. According to H.H. Mitchell, Journal of Biological Chemistry 158, the brain and heart are composed of 73% water, and the lungs are about 83% water. The skin contains 64%...

These dissolve in water, which makes it possible for them to reach different parts of the body.

Dehydration can affect brain structure and function. It is also involved in the production of hormones and neurotransmitters. Prolonged dehydration can lead to problems with thinking and reasoning.

Water is needed in the processes of sweating and removal of urine and feces.

Blood is more than 90 percent water, and blood carries oxygen to different parts of the body.

The kidneys regulate fluid in the body. Insufficient water can lead to kidney stones and other problems.

Saliva helps us digest our food and keeps the mouth, nose, and eyes moist. This prevents friction and damage. Drinking water also keeps the mouth clean. Consumed instead of sweetened beverages, it can also reduce tooth decay.

A lack of water can cause blood to become thicker, increasing blood pressure.

With dehydration, the skin can become more vulnerable to skin disorders and premature wrinkling.

The middle layers of the skin and the stored water in these work like a radiator for the body. When the body temperature rises, the water accumulate the heat and starts to evaporate, cooling the body. 

The bowel needs water to work properly. Dehydration can lead to digestive problems, constipation, and an overly acidic stomach. This increases the risk of heartburn ...