Urine is a liquid waste product of the human body. It is produced in the kidneys where the blood is filtered. During the filtration process, unnecessary nutrition, toxins, waste products and some water are removed from the blood and passed into the urinary bladder. The bladder collects urine throughout the day. It signals the desire to urinate when it is nearing its full capacity. Urine is a useful body fluid for diagnostic testing. It could be used to establish the presence of illegal substances in the body as well. A urine test can be used to understand the underlying cause for various different medical conditions that can affect an individual.
A urine test requires the patient to deposit some urine in a jar which is then sent to a laboratory for analysis. Depending on the suspected condition or type of test, the sample may be collected in the morning, at night, or at any time during the day. Typically, testers request patients to collect their samples from the first bit of urination because this urine is likely to contain more contaminants if these contaminants are present in the urethra or at the mouth of the bladder.
Millions of red blood cells pass out of the body through the urine. These cells are destroyed cells that are cycled out of the body. New red blood cells are produced to replace the dead cells. When the concentration of red blood cells in the blood increases, it is a condition known as hematuria. In mild cases, hematuria is characterized by a small amount of blood in the urine which may not be detectable by the naked eye. Acute hematuria is likely to be obvious with the color of the urine changing to a darker red or brown shade. Acute hematuria should be treated as a medical emergency and can be used to diagnose conditions such as urinary tract infection that has caused the urethra to become inflamed and for the tissue within the urinary system to be damaged, causing bleeding. In many cases a urine test for blood may reveal an elevated level of red blood cells but this is not necessarily a diagnosis of some problem. Sometimes, the level of red blood cells rises, especially after strenuous physical activity. If hematuria is caused by a urinary tract infection, the patient is likely to experience pain while urinating. Other causes of hematuria include kidney and bladder damage.