In type 1 diabetes, an increase in blood pressure usually develops after 10–15 years from the onset of the disease and is usually caused by diabetic nephropathy, and only in a small percentage of cases an increase in blood pressure may be a manifestation of other renal diseases. In the literature there are data on the combination of DM type 1 and chronic glomerulonephritis. In patients with type 1 diabetes, there is a tendency to an increase in blood pressure already at the stage of microalbuminuria, long before the development of clinical signs of nephropathy, which occurs in 30-40% of patients with type 1 diabetes. Arterial hypertension in diabetic nephropathy leads to more rapid progression of the development of chronic renal failure. Thus, in patients with type 1 diabetes, the presence and severity of hypertension is predominantly associated with nephropathy, although in each particular case, as we have already noted, it may be necessary to have a differential diagnosis to exclude other renal lesions.