Dehydration is defined as not having enough water or fluids in the body. Dehydration is caused by either excess water loss or lack of enough water required for the body. Some common dehydration causes include vomiting, diarrhea, excessive sweating, uncontrolled urine passage, fever and conditions that limit intake of water like unconsciousness. Severe dehydration is life threatening and produces several characteristic symptoms.
Symptoms from the Skin and Mucous Membranes
In severe dehydration, the skin is dry and cold with loss of elasticity, called skin turgor. The eyeballs are sunken into the skull, and there are no tears or sweat. The mouth is dry and the tongue sticks to the roof of the mouth. The skin over the scalp in small children is sunken in places overlying the fontanelles (openings in the skull bones for continued growth of the brain outside the womb). There are also obvious signs of rapid weight loss, sometimes up to 50 percent in children, with floppy and wrinkled skin folds.
Heart and Blood Vessels
There is a drastic reduction in blood volume and a corresponding drop in blood pressure sometimes below recordable levels. The heart beats fast and the pulse is thready, if felt at all. Rising from the lying or sitting position to the upright position causes the blood pressure to drastically reduce or even disappear (a condition called postural hypotension). The combination of unreadable blood pressure and a barely palpable pulse define the clinical condition that is called shock, which is a state of insufficient blood supply to the tissues of the body.
The Brain
There is a strong sense of thirst, dizziness and weakness in early stages. The dizziness is made much worse on standing up and may result in blackouts and fainting. Breathing is fast and shallow. There is blurring of vision or double vision. Confusion and delirium may develop as the condition persists. In extreme cases, convulsions and coma may result.
The Kidneys
There is initially very little urine production. As blood flow to the kidney remains low, the kidneys stop producing urine with the rapid buildup of poisonous nitrogenous waste in the blood stream. The kidneys are quickly and irreversibly damaged by severe dehydration. The toxins compound the problems in the brain.
In Conclusion
Severe dehydration is a medical emergency that requires hospitalization and critical care. Some of the effects of severe dehydration are not immediately reversible and may require long-term treatment for recovery. If left untreated, the kidneys may suffer irreparable damage needing dialysis and a kidney transplant.
