If a diabetic patient has red-coloured urine, if the patient does not feel uncomfortable, it may be that foods with pigment inside the diet cause the urine to be red. If the patient has inflammation of the urinary tract, the inflammation can cause the mucous membrane of the urethra to become congested and red blood cells from the ruptured small blood vessels enter the urine making it red.
There is also the possibility of many macrovascular and microvascular complications in diabetics. These complications, if they occur in the kidneys or in the lining of the bladder or ureter, can cause the blood vessels to rupture and bleed, which can also lead to haematuria making the urine red. Some people with diabetes are allergic to glucose-lowering medication or have haemolysis, which causes red urine.
Whatever the cause, diabetics with red urine or a colour that was not previously present should be seen promptly by an endocrinologist specialist.