Nitrites in urine
A urinalysis is one of the most common and affordable ways to test for presence of abnormalities in urine. It helps detect and confirm many different parameters, including the occurrence of nitrites in urine.
Nitrites in urine is not the same as nitrates in urine. The nitrate content in urine is substantially lower. This is one of the reasons why doctors typically look for nitrite content when perusing a urinalysis result.
Healthy people will usually have a ‘not present’ or an ‘absent’ marked beside the nitrites option in the results of a urinalysis. The urine test results of people with a UTI or urinary tract infections will however have a ‘+’ or ‘present’ noted down beside nitrites in urine. The presence of nitrite content in urine needs to be further evaluated via additional tests that will help determine the underlying cause of the condition.
In most instances, the diagnosis of nitrites in urine generally points to the occurrence of some kind of bacteria that have the capability to turn non-ionic nitrates into nitrites. Doctors can subsequently infer that the urine specimen may be contaminated with bacteria, which in turn can indicate the presence of a UTI in the patient.
There are many different types of bacteria and pathogens such as E. coli, Pseudomonas, Proteus Sp., and klebsiella which can cause an infection of the urinary tract. It is important to be aware of all types of germs that can cause UTIs as well as the bacteria types that have the capacity to turn nitrates into nitrites of the gram negative type.
In most cases, a UTI can be easily identified by the presence of gross hematuria which causes the urine to become pinkish, reddish, or cola-colored. Later, a urinalysis that shows nitrites in urine can help confirm the diagnosis of an underlying case of urinary tract infection.
It is also essential to note that the non-detection of nitrites in urine is in no way a conclusive proof that the patient is not affected by a UTI. It can only be effectively ruled out after carrying out many other tests which also offer negative results of any infection.
Urine analysis in a laboratory
It is important for a patient or the lab technician to remember a few important points when checking the presence of abnormalities in a urine sample. This will help avoid misinterpretation of the results.
Contamination of the urine specimen with phenazopyridine can possibly lead to false positive values for nitrites in urine. Phenazopyridine is a kind of chemical with analgesic properties.
Contact of atmospheric air with the dipstick, or vaginal contamination of the urine sample can also result in miscalculated urine test values. In such instances, the presence of nitrites in urine may come out as false positive.
It is possible to get false negative results for nitrites in urine, when the urine sample provided by the patient has elevated levels of urobilinogen. It can also happen in instances of specific gravity, or due to presence of bacteria that do not possess the ability to turn nitrates into nitrites.
Additionally, false negative results for nitrites in urine can also arise when the pH value in urine is lower than 6, or when the patient adheres to a diet that does not include any nitrate content.
Symptoms of nitrites in urine
The occurrence of nitrites in urine may be accompanied by the below listed signs and symptoms:
The urine may be discolored
Elimination of a foul smelling urine
Difficulties or problems in easy passing of urine
Burning sensations during urination
Frequent urge to urinate
Causes of nitrites in urine
Nitrites in urine are formed as a by-product in people affected by bacterial infections of the urinary tract. It may be noted that the kidneys are responsible for filtering blood and removing all the waste products from the body. The kidneys however do not have the ability to filter out nitrites, which then pass into the bladder and stay there. Later, they are eliminated from the body along with the urine. It is therefore widely understood that nitrites in urine generally point to the presence of a urinary tract infection.
UTIs can be caused due to infection of the urinary system by bacteria. The pathogens can enter the tract through the bloodstream, or via direct contact with the skin of the urethra.
The anatomy of women, wherein the urethra is located at close proximity to the vagina and the anus, increases the susceptibility of women to developing UTIs more frequently than men.
People who use bladder catheters are also more vulnerable to developing urinary tract infections.
Treatment of nitrites in urine
Urinary tract infections caused by bacteria are generally treated with correct antibiotics.
Other causes of nitrites in urine are treated as per the standard treatment procedures associated with the underlying causative disorder.