Why do urine tests require “midstream urine”? Will the front and back urine affect the results?

Review expert: Cao Qingwei, deputy chief physician of urology department, Shandong Provincial Hospital

As my parents get older, I have to persuade them to have regular physical examinations every year. Early physical examinations and early prevention are not empty words. Now more and more people are beginning to pay attention to physical examinations. In addition to the mandatory physical examinations before employment, many people have begun to take the initiative to have physical examinations once a year.

Physical examination is an early screening of the body, which is helpful for preventing diseases, but I still have some aversion to a certain project. I still remember the difficult process of doing urine test in the toilet during the first physical examination before employment...

Source: Baidu Encyclopedia

Although there are some small shadows, for the sake of good health, all the items in the physical examination must be included, not to mention that urine test is very important in the physical examination. Many people have done urine tests, but do you know what urine tests are for?

What can a urine test detect?

Urine test, as the name implies, is a method of testing urine. Urine is a metabolite excreted from the body through the urinary system and urinary tract. The daily urine volume of a normal person is about 1000ml-2000ml, so urine testing can reflect the physical condition to a large extent.

As one of the three major routine physical examination items , urine tests can screen for diseases of various organs in the body, mainly the kidneys, such as whether there is a urinary tract infection, diabetes, liver problems, etc.

Source: Baidu Encyclopedia

The process of urine testing is to select multiple indicators from the extracted urine for testing. The main indicators are as follows:

1. Basic tests, including color, pH, and specific gravity;

2. Diabetes-related tests, including urine sugar and ketone bodies;

3. Liver and kidney related tests, including bilirubin, urobilinogen, urine red blood cells, and white blood cells;

4. Protein testing, including urine protein.

After checking the above indicators, we can judge the health status of the human body by checking whether each indicator is normal, so as to do further screening and diagnosis.

What should we pay attention to when doing a urine test?

General physical examinations are conducted in the morning, and you need to stay fasting for 8-10 hours and cannot drink water. Urine test specimens usually require morning urine, so it is best to do a urine test after a routine blood test and other fasting blood tests to avoid long intervals, drinking water when thirsty, diluting the urine, and affecting the urine state.

After arriving at the hospital, the nurse will provide you with a plastic tube and a plastic cup. Before extracting urine, make sure the container is dry and clean.

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The urine collected needs to be midstream urine, so when extracting urine, some urine should be discharged first to help clean the area around the urethra opening and prevent impurities in the urethra opening from interfering with the test results. The extracted urine is midstream urine, and the last part of the urine may contain bladder sediment, so it is not collected. After collecting, just give it to the nurse for testing.

In addition, if you are taking vitamin C, try to stop taking it 3 days before the urine test. Female friends should avoid taking urine tests during their menstrual period.

How to read urine test report?

After the urine test, we patiently waited for the results. As mentioned before, we need to judge the physical condition based on the indicators in the urine test report. If an indicator is positive, there may be some problems. There are so many indicators in the report, what do they mean? Let's follow the editor to look at them one by one:

1. Basic test indicators: color, pH, urine specific gravity

Healthy urine is clear and light yellow. If there is a disease, the color of urine will change. For example, if the urine is turbid, there is a high probability of urinary tract infection. The pH value of morning urine is about 6-7, which is normal within the pH range. If the pH value and urine specific gravity are abnormal, it may be related to nephritis, or it may be affected by diet and activity status. If there is a problem, you can have a follow-up examination in time.

2. Diabetes-related indicators: urine sugar, ketone bodies

Urine sugar refers to the glucose in the urine. If the urine sugar test is positive, diabetes needs to be checked. Ketone bodies are metabolic products. When they are positive, there are many possibilities, such as diabetic ketoacidosis, strenuous exercise, metabolic disorders caused by vomiting and fasting, etc.

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3. Liver and kidney related indicators: bilirubin, urobilinogen, urine red blood cells, white blood cells

Patients with hemolytic jaundice and acute hepatitis will have a "+" sign in their urine. Jaundice is also related to bilirubin, and a specific diagnosis requires checking the total bilirubin concentration in liver serum. Abnormal red blood cells in the urine and a "+" sign in the urine for occult blood require screening for urinary tract stones, tumors or infections. Abnormal white blood cells may indicate urinary tract infection, etc.

4. Protein test: Urine protein

There is generally no protein in urine, but kidney disease will reduce protein absorption and increase the protein content in urine. Therefore, when urine protein is positive, it should be taken seriously, and urine routine should be rechecked or further examined to prevent early kidney disease.

Seeing this, everyone must be very surprised that a simple urine test report analysis can be related to so many possible diseases. It can be seen that urine test is a very important physical examination item, which plays a great role in disease screening and early intervention.

Despite this, you don’t need to be too anxious when you see a “+” sign and a positive result in the analysis report. Although urine tests can reflect a certain physical condition, they are easily affected by external factors, such as diet and rest status before the urine test. Therefore, the editor recommends that you maintain a normal schedule and a light diet before the physical examination so that the test results can accurately reflect your physical condition.

Source: pixabay

Of course, physical examinations only play a role in screening and prevention. Real health still depends on daily management. Make management a habit and make health a habit.