What happens in the kidney
The kidney consists of approximately one million filtering units called nephrons. With prolonged damage, some of them die, and in their place connective tissue is formed that does not filter the blood. The remaining nephrons take on the load, work with overstrain and gradually also become sclerotic. This creates a vicious circle in which the organ decreases in volume and function decreases. A distinction is made between primary nephrosclerosis, associated with damage to the kidney vessels due to hypertension and atherosclerosis, and secondary nephrosclerosis, the outcome of inflammatory and metabolic diseases of the kidneys.
- Primary - hypertensive and atherosclerotic
- Secondary - after glomerulonephritis and pyelonephritis
- Diabetic nephropathy as a common cause
- Unilateral - for example, after a long-term disturbance of the outflow of urine
- Bilateral - leads to chronic kidney disease
Causes and risk factors
The main culprits are conditions that damage the blood vessels and glomeruli of the kidneys over the years. High pressure gradually thickens the walls of the renal arterioles and impairs blood supply to the tissue. Elevated blood sugar damages the glomerular basement membranes. Chronic pyelonephritis and recurrent obstruction of urine outflow due to stones or prostate adenoma lead to scarring. A separate role is played by long-term uncontrolled use of non-steroidal anti-inflammatory drugs.
- Arterial hypertension
- Diabetes mellitus
- Chronic glomerulonephritis
- Chronic pyelonephritis and urine reflux
- Urolithiasis and hydronephrosis
- Atherosclerosis and renal artery stenosis
- Long-term use of painkillers without medical supervision
Symptoms
In the early stages there are no complaints: the kidneys have a large margin of safety, and the first changes are visible only in tests. Later, high blood pressure appears, which is difficult to treat, night urination, and fatigue. With a significant decrease in function, swelling, anemia, itching, nausea and loss of appetite occur. If one kidney is affected and the other is healthy, there may be no symptoms at all, and the ultrasound finding becomes incidental.
- Persistent increase in blood pressure
- Frequent urination at night
- Weakness and decreased performance
- Swelling under the eyes and on the legs
- Pale skin due to anemia
- Decreased appetite and nausea in later stages
Diagnostics
The basis of the examination is the assessment of kidney function using blood creatinine with calculation of glomerular filtration rate, as well as a general urine test and protein determination. Ultrasound shows a decrease in the size of the kidney, thinning of the parenchyma and an increase in its density. Doppler ultrasound helps assess blood flow and suspect renal artery stenosis. If necessary, computed tomography is performed, and to clarify the cause of glomerular damage in specialized centers, a kidney biopsy is performed.
- Creatinine and blood urea, GFR calculation
- General urine analysis and protein in urine
- Albumin-creatinine ratio
- Ultrasound of the kidneys with assessment of size and parenchyma
- Dopplerography of renal vessels
- MSCT of the kidneys with an unclear picture
Treatment and prevention
Scar tissue cannot be dissolved, so the goal of treatment is to preserve remaining function and stop progression. Tight control of blood pressure and blood sugar, as well as reducing protein loss in urine, are key. The doctor selects medications that have a protective effect on the kidneys and adjusts the diet in terms of protein and salt. It is important to avoid self-administration of painkillers and any nephrotoxic drugs. If there is a significant decrease in function, preparation for renal replacement therapy is discussed.
- Target blood pressure as recommended by your doctor
- Glycemic control in diabetes
- Nephroprotective drugs as prescribed
- Limit salt, moderate protein intake
- Quitting smoking and self-medicating with painkillers
- Treatment of urinary tract infections and removal of obstructions to the flow of urine
- Regular monitoring of creatinine and urine analysis