A diuretic is defined as something that increases formation of urine and it has many uses.
Management of edema
Congestive Heart Failure (CHF): The edema is in the lungs in this case and it is the most serious edema. It’s usually not just the pulmonary side but also the venous side in the lower extremities and their legs become huge.
Cranial edema occurs from trauma to the brain or surgery and diuretics are used to decrease cranial pressure.
Ascites is the build up of fluid in the abdominal cavity (people with alcohol/liver disease experience this).
Maintain urine flow and shock: The kidneys are affected and urine output drops when someone is going to go into shock.
Protect from nephrotoxic agent: We haven’t talked about nephrotoxic drugs yet but there are some drugs that we have to use for strong reasons (antibiotics; chemotherapy) that damage the kidney. They work for the intended treatment but damaging when they’re eliminated by the kidney, so we have to dilute the drug and push them through the kidney as fast as possible. So we give them fluids and a diuretic so there is minimal contact.
Glaucoma: Diuretics are used to decrease intraocular pressure (to remove aqueous humour).