Why do people with diabetes urinate a lot?

[poppyj]

.... and are often thirsty? whats it got to do with osmosis? xxx

[TheHitMaker]

People with diabetes are lacking insulin, which removes unnecessary sugar from the blood. If diabetes is not well controlled and the blood sugar level is allowed to rise, then the body will try other methods to get rid of this unwanted sugar. One of these methods is to use the kidneys to try and remove the excess sugar, which then try to get rid of this sugar through the urine. Another obvious side effect of this is that the diabetic will suffer intense thirst to make up for all the liquid which has been lost. Osmosis is to do with liquids of different densities passing across a membrane - which is how the kidneys work perhaps.