For the body, stress means an imbalance that can survive by mobilizing its strength and using the accumulated reserves. Such functioning of the system “at full capacity” can not last too long, therefore long-lasting, chronic stress can bring fatal health effects.
For the system it does not matter whether the disorder of homeostasis was caused by psychological factors (eg stress caused by work) or lack of water. Thus, dehydration is treated by the body as a stressful situation and then it activates the same defense mechanisms. The body reserves are mobilized, the body reaches to the deepest water resources. Under stress, the body goes for hormones that would otherwise not be used. The body uses very strong hormones as long as it is in a situation that it considers to be stress. These are endorphins, increasing resistance to pain, cortisone initiating the process of mobilizing stored raw materials and energy, prolactin and vasopressin, which protects the cells from the loss of too much water.

Dehydration is treated by the body as a stressful situation. The body reserves are mobilized, the body reaches to the deepest water resources. Under stress, the body goes for hormones that would otherwise not be used. For the system it does not matter whether the social stress or dehydration is the cause of stress, it always follows the same pattern. The body uses very strong hormones as long as it is in a situation that it considers to be stress.
Endorphins are their task to prepare the body for hardship and survival until the danger passes. They also increase resistance to pain.
Cortisone is a hormone that initiates the process of starting stored raw materials and energy. If, on the other hand, cortisone activity is prolonged, a selective amino acid deficiency may occur. Under the influence of cortisone, the body gradually uses its own resources. The prolonged activity of this hormone causes the greatest damage to health associated with stress, if it is continuous.
The next hormone is prolactin. It is produced in the mother’s nursing body, so that even in the situation of dehydration and stress causing dehydration the body produces milk.
Every time a cell divides and a new one is created, water is needed to fill 75% of its volume. The increase depends on the amount of water available.
Vasopressin regulates the selective inflow of water to certain body cells and shrinking of capillary blood vessels. Wazopressin protects the cell from the loss of too much water, which could affect its functioning. When there is a shortage of water and its inflow into the cell is insufficient, the water is filtered through the cell membrane. When vasopressin reaches the cell, it connects to a special receptor, which turns into a kind of “shower screen” and allows only water to flow through its openings. Cells of greater importance to the body produce vasopressin receptors in larger amounts. Nerve cells are the priority here.