Anti aging guide

Dehydration and Kidney Function



Why are old people liable to dehydration and what is like to be dehydrated?

We have seen that one reason is the deterioration in kidney function that many, if not necessarily all old people suffer. There are, however, other mechanisms involved in maintaining the water level – of the body, for instance, the sensation of thirst which prompts us to drink. There is evidence that this mechanism often does not work so well, or is less sensitive to minor degrees of water depletion, in many elderly people. In addition, people may ignore the sensation of thirst because of depression, or immobility, or swallowing disorders, or because they are afraid of needing to empty the bladder at a socially inconvenient time. Finally, many elderly people are prescribed diuretic tablets for fluid overload, and if taken on a long-term basis these can seriously deplete the body of water, sodium, and potassium. Excessive quantities of urine are also produced in certain diseases such as diabetes.

Failure to drink enough leads to predominant water deficiency and the portion of the body’s fluid mainly affected is that within the cells, typically leading to thirst and eventually to weakness and confusion. But if quantities of fluid are lost through vomiting, diarrhoea, or excessive urine excretion, there is variable loss of salt, water, and potassium, and this mixture is often partially replaced by drinking water or other fluids containing inadequate quantities of electrolyte. This leads to depletion of the portion of the body_’s fluid in the tissue spaces and eventually to a fall in the circulating blood volume. This form of dehydration accompanied by salt loss is much less likely to evoke the sensation of thirst. It results in profound weakness and dizziness caused by a fall in blood pressure, and contributes to the sunken eyes and pinched cheeks so characteristic of grave illness.

Posted by Carol Hudgens - April 27, 2012 at 11:30 am