Diabetes causes excess glucose in the bloodstream, along with other fluids from the body, to be secreted into the urine, causing the urine to have more sugar than normal, says Mayo Clinic. This extra sugar and fluids create the need for more frequent urination, resulting in dehydration.
The dehydration creates excessive thirst, which results in more water intake and leads to increased urination, explains Mayo Clinic. Excessive thirst and frequent urination are two leading symptoms of diabetes.
Diabetes can harm the kidneys by overworking them. The kidneys filter more blood than usual when the level of blood sugar in the body is too high, notes the American Diabetes Association. Normally, the kidneys filter waste products from the bloodstream into the urine. The filters, which are tiny capillaries lined with even smaller holes, retain useful substances such as protein and red blood cells. When the kidneys work too hard, the holes in the capillaries leak, and protein is deposited into the urine.
When there is a small amount of protein present in the urine, this condition is called microalbuminuria, and there are several treatments for it, according to the American Diabetes Association. Large amounts of protein in the urine, referred to as macroalbuminuria, can lead to end-stage renal disease and kidney failure. Patients with kidney failure require transplants or dialysis.