What is a urine test?
A urine test – also known as a urine examination or urinalysis – analyzes the quantity, color, odor, microscopic components and 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 via the urine. It can also regulate its water balance by increasing or decreasing urine excretion.
When is a urine test carried out?
Basically, a urine test is always necessary if the doctor wants to determine the exact composition of the urine. Substances that are not found in the urine of a healthy person and urine values that deviate from the norm can indicate a disease. Pregnancy can also be detected via the urine.
Specifically, a urine test is carried out in the following cases:
- if a urinary tract infection (e.g. cystitis) or other urinary tract or kidney diseases are suspected
- to monitor the progress of such diseases
- to detect blood in the urine
- to detect protein in urine and sugar (glucose) in urine, for example to detect diabetes mellitus
- as a pregnancy test
What do you do with a urine test?
If your doctor asks you to provide a 24-hour urine sample, all the urine is collected in a single container over 24 hours.
In exceptional cases, the doctor collects the urine sample himself via a catheter inserted into the bladder.
Quantity, color and odor
The quantity, color and odor of the urine passed can already indicate possible health problems. For example, if the patient excretes only a small amount of dark urine, this may be due to either insufficient fluid intake or impaired kidney function. If blood is found in the urine test, the reason may be a urinary tract infection (e.g. bladder or kidney inflammation). A foul odor indicates an inflammation.
Determination of various substances in the urine
Multiple divided test strips are used for a quick urine test. They can be used to determine various substances in the urine, with indicator fields on the test strips changing color depending on the concentration of the substances. The intensity of the coloration 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
- Red blood cells (erythrocytes) in the urine: inflammations, infections, rarely tumors
- White blood cells (leukocytes) in the urine: inflammations, infections
- Nitrite in 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 test result is below five, the urine is too acidic. Possible reasons for this are, for example, high fever, gout and a diet rich in meat. If the pH value is above seven, the urine is too alkaline (basic). This can be the case, for example, if you have a urinary tract infection – or if the urine sample has been standing around for too long before the pH value is determined.
Microscopic urine analysis
The so-called urine sediment is obtained from the urine sample by centrifugation. This is the solid components of the urine, for example exfoliated epithelial cells from the urinary tract, red and white blood cells, cylindrically shaped proteins and bacteria. The microscopic assessment of urine sediment can support the diagnosis of urinary tract diseases.
Urine culture
Based on the results of various urine tests, the doctor can make a diagnosis and initiate appropriate treatment. For example, if the urine smells strong and the indicator fields of the test strip for increased pH, white blood cells and waste products from bacteria are discolored, this indicates a urinary tract infection. For further clarification, the bacteria causing the infection can be detected in a urine culture.
What are the risks of a urine test?
A normal urine test is an examination without complications. However, bacteria, the intake of large amounts of vitamin C or incorrect storage of the urine sample can falsify the results. If the urine sample is taken using a catheter, there is a risk of infection and injury to the urethra.
What do I need to consider after a urine test?
Your doctor will discuss the results with you in detail and explain further treatment in the event of deviating urine values or other changes. While the microscopic examination and urine culture are carried out in the laboratory, you can buy test strips over the counter from the pharmacy to examine your urine at home. However, this does not replace a visit to the doctor and a professional urine test.
