Urine is a liquid byproduct of the body that is secreted by the kidneys. It passes through the ureter (the tubes joining bladder and kidney), bladder (bag where urine is collected) and finally excreted through the urethra (passage for the urine to flow out of the body). In a healthy person, urine is sterile, which means it does not contain any disease causing germs. During the secretion of urine, there may be certain chemicals that go out with it. These chemicals are detected during urinalysis. Some chemical secretions indicate an important bodily condition or it may have no bearing at all.
Essentials of Urine Tests
A urine test is run to examine and evaluate the different components of urine. Urine analysis can give information about your health and illnesses that you may have. Almost 95% of urine is made up of water. A routine urinalysis will include the following tests:
- Color: Tells you how much water is present in it. Usually the urine color is pale yellow to colorless in a healthy individual. The yellowish tinge is due to Urobilinogen, a final waste product resulting from breakdown of aging red blood cells. Color of urine that is similar to water is due to over hydration, but in dehydration the color changes to dark yellow.
- Clarity: May indicate the presence of white particles floating in urine. The white particles can make the urine look cloudy. It can be due to the presence of bacteria or due to calcium phosphate crystals. Sometimes vaginal discharge in women can contaminate the urine and make it look turbid.
- Odor: No strong smell is observed, but it has a slightly “nutty” odor. However, eating certain foods can influence urine smell. For example, after eating asparagus, alcohol, onion, garlic, the urine will smell more than normal.
- Specific Gravity: Checks the amount of substances in the urine.
- pH: Measures the level of acidity.
- Glucose: In healthy individuals, urine does not contain glucose. However, a person suffering from diabetes passes glucose in his urine.
- Nitrites: They are present in the urine persons diagnosed with urinary tract infection (UTI).
- Leukocytes: May indicate that the person is suffering from UTI.
Floating Particles in Urine
A microscopic analysis can reveal the following floating things in urine:
- Blood Cells: Normally, urine is free from any blood cells. At most, one or two blood cells may be found in one field. An injured and diseased kidney or the urinary tract can cause excessive bleeding. When there are innumerable blood cells in urine, the color of the urine changes to red. They may also appear as floating particles.
- Casts: Material formed in the kidney tubes, called casts, may be expelled through urine. Usually there are different types of casts. Different kidney diseases expel different casts. These floating items in urine are not very common.
- Crystals: Crystals are amorphous materials present in the urine. In a healthy individual, a few crystals are normally detected on microscopic examination of the urine. However, if a person is suffering from “kidney stones”, there will an abnormal quantity of crystals in the urine.
- Floating particles in urine can be seen when you collect urine in a clean bottle. In presence of organisms such as bacteria and parasites, the urine may become turbid. It indicates that there are lot of floating particles in the urine.
- Squamous cells: Sometimes, there is a presence of squamous cells in the urine. Squamous cells are present as a result of contamination such as vaginal discharge. They may not indicate a renal disease. In such cases, the Microbiologist may ask for a fresh new urine sample.