How is kidney function evaluated through a 24-hour urine test?
May 13, 2025
Source: Cainiu Health
Dr. Yang Guang
Introduction
The 24-hour urine test can assess kidney function through methods such as measuring urinary protein, evaluating glomerular filtration rate, analyzing tubular reabsorption function, detecting urinary vanillylmandelic acid, and measuring urinary creatinine and urea nitrogen. If concerns exist, it is recommended to consult a qualified physician. In daily life, one should maintain a healthy lifestyle, improve dietary habits, and engage in appropriate physical exercise.
In general, a 24-hour urine test can assess kidney function by measuring urinary protein, evaluating glomerular filtration rate, analyzing tubular reabsorption function, testing urinary vanillylmandelic acid, and measuring urinary creatinine and urea nitrogen. If concerns exist, it is recommended to consult a professional physician. Detailed explanations are as follows:
1. Measurement of urinary protein: By collecting all urine over a 24-hour period and measuring its protein content, the functional status of the glomeruli and renal tubules can be assessed. The total urinary protein in a healthy individual is less than 0.15g over 24 hours; exceeding this value may indicate the presence of kidney disease.
2. Assessment of glomerular filtration rate (GFR): Glomerular filtration rate is a key indicator for evaluating kidney filtration function. By collecting 24-hour urine and measuring the total creatinine content, the GFR can be calculated.
3. Analysis of tubular reabsorption function: By collecting 24-hour urine and analyzing the total amounts of electrolytes such as sodium, potassium, calcium, magnesium, and phosphorus, the status of renal tubular reabsorption function can be evaluated.
4. Testing urinary vanillylmandelic acid (VMA): Urinary vanillylmandelic acid is a specific marker for pheochromocytoma. By collecting 24-hour urine and measuring the VMA content, diagnosis of pheochromocytoma can be assisted. This condition may lead to serious consequences such as sudden elevation in blood pressure and increased heart rate.
5. Measurement of urinary creatinine and urea nitrogen: Urinary creatinine and urea nitrogen are important indicators reflecting kidney excretory function. By collecting 24-hour urine and measuring the levels of creatinine and urea nitrogen, the kidney's ability to excrete metabolic waste can be assessed.
In daily life, maintaining a healthy lifestyle, improving dietary habits, engaging in appropriate physical exercise, enhancing physical fitness, and reducing the risk of disease are recommended.
