What can urine test reveal

Every time we go to the hospital for a check-up, we will find that urine tests are usually needed because this can detect some potential inflammatory problems in the body, especially those related to the urethra, as well as bladder, kidney and urinary tract infections. By testing urine, we can obtain some standard samples, which can be used for testing. However, avoid checking during menstruation because it is inaccurate.

Specimen collection

The requirements and processing of urine specimens vary depending on the urine examination items. All urine specimens should be collected in clean containers. In principle, the midstream urine of the first urine after getting up in the morning (morning urine) can be collected for urine sediment microscopy. The midstream urine of random urine can also be collected. Morning urine specimens are also suitable for other urine examinations (except 24-hour urine examination items). The determination of renal tubular concentration and dilution function requires fasting for 12 hours before urination, and then fasting for 1 hour. The urine of the 13th hour should be collected for testing. When determining the renal tubular acidification function, liquid paraffin should be added to the urine container in advance. Before collecting the 24-hour urine specimen, a preservative should be added to the container or the container should be placed in a 4°C environment.

When collecting urine specimens, you should pay attention to some special circumstances:

①Female patients should avoid collecting urine specimens during menstruation;

② Urine examination should not be performed on specimens with gross hematuria (except urine sediment);

③ If the medication you are taking affects urine testing, you should collect samples after stopping the medication;

④ If it is chyluria, the patient should be advised to collect the urine after it becomes clear.

Urinalysis

A rapid urine screening test is performed using multiple test strips, also known as a routine urine test. Dipstick methodology is a simple and rapid urine screening method. Currently, routine urine test strip examination items include pH, protein, occult blood, specific gravity, glucose, and ketone bodies. Urobilinogen, nitrate, leukocytes, some test strips also integrate bilirubin and vitamin C, etc.

Although the urine test strip method is quick and simple, it can only play a qualitative and semi-quantitative role due to methodological limitations. The test results may have false positives and false negatives, and the results are affected by many factors.

pH

The kidneys are involved in regulating the body's acid-base balance, and this regulatory ability can be reflected by urine pH. Due to the excessive production of endogenous acid, the urine pH is generally acidic, about 5.0~6.0. Generally speaking, the "alkaline tide" phenomenon will occur after a meal, and the urine will be alkaline; acidic urine is more common in eating too much meat and certain types of fruits (such as cranberries), metabolic acidosis, respiratory acidosis, and the use of stone-excreting drugs (such as calcium carbonate); alkaline urine is more common in eating vegetarian food and citrus fruits, metabolic alkali poisoning, respiratory alkali poisoning, some kidney diseases (such as renal tubular acidosis), etc.

pH testing requires a fresh urine sample. If urine is left for too long, most bacteria can decompose urea and release ammonia, making the urine alkaline. But sometimes the opposite happens; the carbonate buffer in the urine releases CO2, which escapes into the air and increases the urine pH.

[Normal reference value] 5.0 ~ 8.0.