The kidneys are the human body's filtration workshop, and they also work part-time, such as producing endocrine hormones, helping the body control blood pressure, and maintaining bone health. The kidneys contribute greatly and are vulnerable, but the clinical symptoms of early lesions are not obvious. Some patients come to see a doctor and have uremia as soon as they are checked. There are generally three types of renal function tests: blood test, ultrasonography and routine urine test, and routine urine test can be said to be the first choice for kidney "checking posts".
When kidney function tests are abnormal, indicators such as the amount of protein in the urine or the amount of urine change.
(1) Urine volume. Usually, the total amount of urine excreted from the body in 24 hours is 1000-2000 ml. Polyuria may occur in chronic pyelonephritis, hypertensive nephropathy, early chronic renal failure, etc.; in acute glomerulonephritis, acute exacerbation of chronic nephritis, acute renal failure and other diseases, oliguria or anuria may occur.
(2) Color and transparency. Normal fresh urine is pale yellow, clear and transparent. Normal urine microscopic examination of red blood cells is 0, common in acute glomerulonephritis, chronic nephritis, renal tuberculosis, renal tumor or acute cystitis. Normal human urine microscopic examination of leukocytes and pus cells does not exceed 5 / high power field. When this value is exceeded, it may be acute glomerulonephritis, pyelonephritis, and renal tuberculosis.
(3) pH. Under normal dietary conditions, the random uric pH is 4.5 to 8.0. In nephritis, the pH of urine decreases; in renal tubular acidosis, the pH of urine increases.
(4) Protein. The urine protein content of normal people is very small, persistent proteinuria is one of the signs of kidney disease, and it can also reflect the progress of kidney disease.
(5) Urine microalbumin. Usually, the appearance of microalbuminuria is considered to be an early stage of renal disease, and it is a sign of early kidney damage such as diabetic nephropathy and hypertensive nephropathy.
Blood and renal function tests are of great value in guiding the diagnosis and treatment of renal diseases.
(1) Urea. When renal function is mildly impaired, the blood urea value may remain unchanged. When it is higher than the normal value, it means that 60% to 70% of the effective nephrons have been damaged. Therefore, urea determination cannot be used as an indicator of early renal insufficiency, but it has special value in the diagnosis of renal failure, especially azotemia.
(2) Creatinine. When the renal parenchyma is damaged, the glomerular filtration rate will decrease, and when it decreases to a certain extent, the serum creatinine concentration will rise sharply, which is common in glomerular filtration dysfunction caused by various reasons. This also helps to differentiate between prerenal renal failure and renal oliguria.
(3) β2-microglobulin. This is a very sensitive and specific indicator reflecting proximal tubule damage and can better understand glomerular filtration function. Various acute and chronic nephritis, renal failure, diabetic nephropathy, renal tumor, renal transplant rejection, etc. will lead to the increase of this value.
(4) Uric acid. Uric acid is mainly excreted by the kidneys, so measuring serum uric acid can understand kidney function. Acute or chronic nephritis, pyelonephritis, renal tuberculosis, etc. can increase serum uric acid.
(5) Cystatin C. It can be used for early assessment of renal filtration damage in diabetic nephropathy, early diagnosis of renal damage in hypertension, assessment of renal function recovery in patients with kidney transplantation, monitoring of renal function changes in hemodialysis patients, evaluation of renal function in the elderly, diagnosis of pediatric nephropathy, and diagnosis of pediatric nephropathy, monitoring of renal function during chemotherapy, etc.
