During the physical examination, are you the one who has "wrong urine"?

In many social activities, we will do health examinations, such as: conscription physical examinations, employment physical examinations, school admission physical examinations... During the physical examination, most people have heard the medical staff's advice: "When collecting urine, remember to collect the middle urine, that is, it is best not to collect the front and back urine, just keep the middle urine."

1. Why is midstream urine better?

1. Urinalysis is mainly performed by urine analyzer and microscope. Because the initial and final urine of urination may be contaminated by bacteria around the urethra or genitals, the urine test results may be inaccurate.

2. The flushing of the initial urine will carry away some bacteria, and the urethral opening will be relatively clean. The test results of the mid-stream urine can reflect the true condition of the body.

3. There are some substances with low solubility in the posterior urine, such as calcium oxalate, uric acid, etc., which may be over-concentrated in the posterior urine and form crystals or precipitates.

2. What does it mean to urinate correctly?

First, empty the first part of the urine, use the urine cup to collect the middle part, and then empty the last part of the urine. The purpose of collecting the middle part of the urine is to avoid urethral inflammation, leucorrhea, etc., which may contaminate the urine and affect the test results.

3. What else should you pay attention to when collecting urine samples?

1. Morning urine is generally better: Morning urine is the first urine after getting up in the morning. The formed elements such as urine cells and casts are well preserved, less affected by diet and exercise, and more accurate in testing.

2. Avoid contamination: Try to use the containers provided by the hospital and keep them dry and clean. It is best not to do strenuous exercise before the urine test. Female patients should especially avoid vaginal secretions or menstrual blood contaminating the urine, and male patients should avoid semen mixing in; avoid chemical substances (such as surfactants, disinfectants), feces and other contaminants mixing in.

3. After collecting urine, it should be sent for testing as soon as possible: avoid exposing urine to air and causing oxidation reactions that may change its pH, formed components, etc.

4. Don’t force urine when there is no urine: If you force urine when there is no urine, it may cause inaccurate test results. You can drink some water and collect midstream urine when you have enough urine. Also avoid drinking a lot of water to dilute the urine.