What is the definition of diuresis?

            Diuresis 

Diuresis : is something I’ve seen a lot of in a lifetime of treating patients with kidney disease. It simply means a shedding of excess body fluid as urine. There are other ways of losing water, but other terms apply to those. Diuresis occurs if you drink more fluid than you need, because body sensors detect the increase in the volume of your blood and send chemical (hormonal) messages to the kidneys to bump up the urine output until the volume is restored down into the healthy range. The opposite happens of course if you become dehydrated.

In some diseases, like heart failure, the whole sensor-hormone system gets messed up and the body retains fluid (salty water) and gets bloated, meaning not enough urine is produced. Why that happens is complicated. Drugs can be given to force the kidneys to make more urine, so correcting the situation: they are called diuretics. Some foods and drinks contain chemicals that can lead to a diuresis by a similar mechanism.

On the other hand, if the kidneys begin to malfunction because a proportion of the 2 million little filters in them are damaged by disease the initial result is, surprisingly unless you study the reason, that more urine is produced (a diuresis results). The volume of urine is increased, but it contains a lower concentration of natural waste products than it should, so they are retained in the body, and that can make the sufferer feel pretty unwell. Fortunately the kidneys have a large reserve of those little filters, so you need to have a lot of damage to suffer what I have described. Kidney damage like that can be diagnosed by a simple blood test before it gets too severe.