German nutritional expert, Ante Gall, said that fluid deficiency in the body can be inferred by noticing some symptoms.

Gall explained that the symptoms are:

1- Headache.

2- The Vertigo.

3- Weak focus.

4- Kidney pain.

5- Decreased urine output.

6- The dark color and the pungent odor.

7- Constipation and thick stools.

8- Dryness and chapped lips.

9- The appearance of wrinkles on the back of the hand, forearm and thigh.

Gal noted that the lack of fluids in the body is mostly due to a decreased feeling of thirst due to age or injury to a disease, stressing the need to supply the body with fluids adequately at a rate of not less than a liter and a half per day.