Early kidney disease has no symptoms? These 4 tests can help you detect and treat it early

Among all kinds of chronic diseases, the hidden nature of kidney disease is a headache. Many patients are unaware of kidney disease in its early stages. By the time they experience obvious discomfort, such as edema, fatigue, and backache, the condition has often developed to a more serious stage, making treatment much more difficult, and they may even face the risk of kidney failure. In fact, early detection of kidney disease is not without traces. With the help of these four examinations, you can keep a check on kidney health and achieve early detection and early treatment.

Urinalysis: a barometer of kidney health

Urinalysis is the most basic and commonly used examination method for screening kidney disease. It can directly reflect whether the excretion and filtration functions of the kidneys are normal. Under normal circumstances, urine should not contain substances such as protein, red blood cells, and white blood cells. Once the kidneys are damaged, the filtration function of the glomeruli and the reabsorption function of the renal tubules become abnormal, and these substances may "slip" into the urine.

Protein is an important "barometer" of kidney disease. When proteinuria appears in the urine, especially microalbuminuria, it is likely a "distress signal" from the kidneys. Microalbuminuria may not be detected by the naked eye in the early stages, but it can be detected through qualitative and quantitative detection of urine protein in routine urine tests. For example, in the early stages of diabetic nephropathy, patients often first develop microalbuminuria, which then gradually develops into clinical proteinuria, and kidney function also declines.

The presence of red blood cells should not be ignored. Microscopic hematuria, that is, more than 3 red blood cells per high-power field of view under a microscope after centrifugation, may be a manifestation of diseases such as glomerulonephritis, urinary stones, and tumors. Leukocytosis indicates the possibility of urinary tract infection. If not treated in time, the spread of inflammation may cause pyelonephritis and damage the kidney substance.

In addition, urine specific gravity, pH, urine sugar and other indicators can also provide important clues. For example, abnormal urine specific gravity may reflect impaired kidney concentration and dilution functions; positive urine sugar may be related to impaired renal tubular reabsorption after excluding diabetes. Urinalysis is simple and inexpensive, and it is recommended to be performed at least once a year. For people with high-risk factors such as hypertension, diabetes, and obesity, the frequency of examinations should be appropriately increased.

Renal function test: a touchstone for evaluating kidney function

Renal function tests mainly evaluate the excretion and metabolic functions of the kidneys by detecting indicators such as creatinine, urea nitrogen, uric acid and cystatin C in the blood.

Creatinine is a product of muscle metabolism and is mainly excreted through the kidneys. When kidney function is impaired, creatinine excretion decreases and the creatinine level in the blood increases. Serum creatinine is an important indicator of kidney function, but it may not be sensitive in the early stages of kidney damage because the kidneys have a strong compensatory capacity. Only when the glomerular filtration rate drops to a certain level will serum creatinine increase significantly.

Urea nitrogen is also the end product of protein metabolism, and its level is affected by many factors, such as high-protein diet, infection, fever, gastrointestinal bleeding, etc. Therefore, it is not accurate to evaluate renal function based on urea nitrogen alone, and it needs to be combined with other indicators for comprehensive judgment.

Uric acid is a product of purine metabolism, and about two-thirds of it is excreted through the kidneys. Hyperuricemia is not only a risk factor for kidney disease, but may also directly lead to the deposition of urate crystals in the kidneys, causing gouty nephropathy. Regular testing of uric acid levels is essential for the prevention and early detection of kidney disease.

Cystatin C is a renal function indicator that has received much attention in recent years. It is not affected by factors such as age, gender, and muscle mass, and can reflect changes in glomerular filtration rate earlier and more accurately. In the early stages of kidney disease, when blood creatinine and urea nitrogen are still within the normal range, cystatin C may have increased, providing an important basis for early diagnosis. It is recommended that people with high-risk factors for kidney disease have regular renal function tests to detect subtle changes in renal function in a timely manner.

Renal Ultrasound: A "X-ray Eye" to Insight into Kidney Structure

Renal ultrasound scans the kidneys using ultrasound waves, which can clearly show the size, shape, structure, and blood flow of the kidneys. Ultrasound examinations can reveal congenital abnormalities of the kidneys, such as polycystic kidney disease and horseshoe kidney. Polycystic kidney disease is a common hereditary kidney disease. In the early stages, the kidneys may only show a few small cysts. As the disease progresses, the cysts gradually increase and enlarge, compressing normal kidney tissue and causing renal damage. Ultrasound examinations can detect polycystic kidney disease early and provide timely intervention and treatment for patients.

In addition, ultrasound examination can also detect kidney stones, tumors, hydronephrosis and other lesions. Kidney stones can cause symptoms such as renal colic and hematuria. Long-term presence may also lead to hydronephrosis and renal damage; kidney tumors may be life-threatening. Early detection of these lesions is crucial for treatment and prognosis. Kidney ultrasound examination is non-invasive and convenient. It is one of the important means of screening for kidney disease and is recommended to be performed once a year.

Urine microalbumin/creatinine ratio (UACR): an early warning indicator of kidney damage

UACR is a sensitive indicator for evaluating early renal damage, especially for patients with diabetes and hypertension. In the early stages of kidney disease, the amount of urinary protein excretion may be small, and it is difficult to detect it through routine urine tests, but by testing UACR, these trace amounts of albumin can be captured in time.

Diabetic nephropathy is one of the common microvascular complications of diabetes, and there are often no obvious symptoms in the early stages. Studies have shown that once diabetic patients have elevated UACR, the risk of renal failure will increase significantly. Timely detection and intervention of elevated UACR, such as strict control of blood sugar and blood pressure, and adjustment of lifestyle, can delay the progression of diabetic nephropathy.

Hypertensive patients also need to pay attention to UACR. Long-term hypertension can lead to sclerosis of renal arterioles, cause glomerular damage, and cause albumin to leak into the urine. Regular testing of UACR can help detect hypertensive kidney damage early, take effective blood pressure reduction and kidney protection measures, and reduce the risk of kidney damage. It is recommended that patients with diabetes and hypertension test UACR every 3-6 months to detect kidney damage early.

Although kidney disease is asymptomatic in the early stages, we can detect kidney abnormalities in a timely manner through urine routine, renal function tests, renal ultrasound, and urine microalbumin/creatinine ratio tests, thus buying precious time for early treatment. Especially for people with high-risk factors such as hypertension, diabetes, obesity, and a family history of kidney disease, they should be more vigilant and conduct these tests regularly to protect their kidney health.