Urine test

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With a urine test, the doctor analyzes a urine sample in order to identify diseases or to assess their course. Simple test strips, microscopic urinalysis and urine cultures are available for this. Read all about the urine test, how it works and the risks it carries.

What is a urine test?

A urine test - also known as a urine test or urine test - analyzes the amount, color, odor, the microscopic components and the chemical composition of a urine sample. The results allow conclusions to be drawn about the patient's health.

The body excretes various substances and toxins through the urine (urine). He can also regulate his water balance through increased or decreased urine excretion.

When to do a urine test

Basically, a urine test is always necessary when the doctor wants to determine the exact composition of the urine. Substances that are not found in the urine of healthy people, as well as urine values ​​that deviate from the norm, can indicate an illness. Pregnancy can also be detected in the urine.

Specifically, a urine test is carried out in the following cases:

• if you suspect a urinary tract infection (e.g. cystitis) or other urinary tract or kidney diseases
• to monitor the progress of such diseases
• for the detection of blood in the urine
• for the detection of protein in the urine and sugar (glucose) in the urine, for example for the detection of diabetes mellitus
• as a pregnancy test

What do you do in a urine test?

For a urine test, a urine sample is first obtained. The first morning urine is best for this. The so-called midstream urine is examined. To do this, do not catch urine at the beginning of urination, but only from the running urine stream. Your doctor will give you a container in advance to collect the urine sample

If your doctor asks for a 24-hour urine sample, all urine will be collected in a single container over a 24-hour period.

In exceptional cases, the doctor himself can obtain the urine sample through a catheter inserted into the urinary bladder.

Amount, color and smell

The amount, color and smell of the urine released can indicate possible health problems. For example, if the patient only excretes a small amount of dark urine, this can either be due to insufficient fluid intake or impaired kidney function. If blood is found in the urine test, the reason could be a urinary tract infection (e.g. bladder or kidney infection). A foul odor indicates inflammation.

Determination of various substances in the urine

Multiply divided test strips are used for a quick urine test. They can be used to determine various substances in the urine by changing the color of indicator fields on the test strips depending on the concentration of the substances. The intensity of the color is compared with special tables, which allows conclusions to be drawn about the concentration of the respective substance. Depending on the substance, the test result can indicate various illnesses or pregnancy:

• Glucose in the urine (urine sugar): diabetes mellitus
• Protein in the urine: kidney disease
• Ketones in the urine: increased fat loss through fasting or derailment of diabetes mellitus
• red blood cells (erythrocytes) in the urine: inflammation, infection, rarely tumors
• white blood cells (leukocytes) in the urine: inflammation, infection
• Nitrite in the urine (produced by germs): infections
• hCG (human chorionic gonadotropin): pregnancy

There are also urine test strips that can be used to determine the acidity (pH value) of the urine. In healthy people this is between five and seven. If the measurement result is below five, the urine is too acidic. Possible reasons for this are, for example, a high fever, gout and a high-meat diet. If the pH value is above seven, the urine is too alkaline (basic). This can be the case, for example, with a urinary tract infection - or if the urine sample has been standing around for too long before the pH value is determined.

Microscopic urine examination

For this purpose, the so-called urine sediment is obtained from the urine sample by centrifugation. These are the solid constituents of urine, for example peeled epithelial cells from the urinary tract, red and white blood cells, cylindrically shaped proteins and bacteria. Microscopic assessment of urine sediment can aid in diagnosing urinary tract disease.

Urine culture

In urine culture, the urine sample is placed on a nutrient medium and placed in an incubator. If the urine contains bacteria or fungi, they will grow well on the culture medium and can then be identified. They can also be tested for drug resistance (e.g. various antibiotics), which can be important for therapy planning.

Based on the results of various urine tests, the doctor can make a diagnosis and initiate appropriate therapy. For example, if the urine smells strongly and the indicator fields on the test strip for high pH, ​​white blood cells and bacterial waste products change color, this indicates a urinary tract infection. For further clarification, the causative bacteria can be detected in a urine culture.

What are the risks of a urine test?

A normal urine test is a straightforward examination. However, for example, bacteria, ingestion of large amounts of vitamin C or incorrect storage of the urine sample can falsify the results. If the urine sample is taken with the help of a catheter, there is a risk of infections and injuries to the urethra.

What do I have to consider after a urine test?

Your doctor will discuss the results with you in detail and explain further therapy to you in the event of deviating urine values ​​or other changes. While the microscopic examination and the urine culture are being carried out in the laboratory, you can buy test strips from the pharmacy without a prescription so that you can independently examine the urine at home. However, this does not replace a visit to the doctor and a professional urine test.

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