Having nitrates in urine is normal and not harmful. However, having nitrites in your urine could mean you have an infection.
Nitrates and nitrites are both forms of nitrogen. The difference is in their chemical structures — nitrates have three oxygen atoms, while nitrites have two oxygen atoms.
Both nitrates and nitrites are found naturally in certain vegetables, like leafy greens, celery, and cabbage, but are also added to processed foods as a preservative.
The presence of nitrites in urine most commonly means there’s a bacterial infection in your urinary tract. This is usually called a urinary tract infection (UTI).
A UTI can happen anywhere in your urinary tract, including your bladder, ureters, kidneys, and urethra.
Harmful bacteria find their way into the urinary tract and reproduce rapidly. Some types of bacteria have an enzyme that converts nitrates into nitrites. This is why the presence of nitrites in urine is a sign that you may have a UTI.
UTIs usually have symptoms you can notice, such as:
- burning with urination
- feeling the need to urinate often without passing much urine
- increased urgency of urination
- blood in the urine
- cloudy urine
- strong smelling urine
Some people won’t experience symptoms of a UTI right away. If you’re pregnant, your doctor may want to test your urine for nitrites and other factors at several points in your prenatal care as a precautionary measure, even if you don’t have symptoms of a UTI.
UTIs are common in pregnancy and are dangerous. They can lead to high blood pressure and premature delivery if left untreated. UTIs during pregnancy are also more likely to spread to the kidneys.
Nitrites in the urine are diagnosed with a test called a urinalysis. This is when you give a sample of urine.
A urinalysis may be done for a variety of reasons, including:
- if you have symptoms of a UTI, like painful urination
- during a routine checkup
- if you have blood in your urine or other urinary problems
- before surgery
- during a pregnancy checkup
- if you’re admitted to a hospital
- to monitor an existing kidney condition
- if your doctor suspects you may have diabetes
Before a urinalysis, inform your doctor of any medications, vitamins, or supplements you’re taking.
Clean catch urine sample
You may be asked to provide a “clean catch” urine sample.
To do this:
- First, you’ll have to clean your genital area well before collecting urine to make sure the sample does not have traces of bacteria and cells from nearby skin.
- As you begin to urinate, first allow some of the urine to fall into the toilet.
- Then collect about 2 ounces of urine in the cup provided by your doctor. Avoid touching the inside of the container.
- ou can then finish urinating in the toilet.
Analysis of the urine sample
There are several steps taken to analyze urine in a urinalysis:
- First, your urine will be visually inspected for cloudiness — cloudy, red, or brown-colored urine usually means there’s an infection.
- Second, a dipstick (a thin stick with strips of chemicals) is used to check for a variety of factors, such as the pH, and the presence of protein, white blood cells, or nitrites. A dipstick test can be done immediately after the sample is taken.
- If the dipstick test reveals abnormal results, the urine sample may be sent off to a laboratory for further testing and microscopic evaluation.
A positive test for nitrites in urine is called nitrituria. Nitrituria by itself may not mean you have a UTI. If you have nitrituria, your doctor may want to send your urine sample to a laboratory for a urine culture test.
In a urine culture, healthcare professionals can find out if you have a UTI and, if so, which bacteria are causing it.
A urine culture usually takes about two to three days to be completed, sometimes longer depending on the type of bacteria. On average, you should expect to see your results in 3 days.
Keep in mind that not all bacteria are capable of converting nitrate to nitrite. So, you can have a negative nitrite test and still have a UTI. This is why your doctor considers the result of many tests and any symptoms when diagnosing a UTI.
If your nitrites represent a UTI, they can become more severe as they spread toward the kidneys.
An infection in the upper urinary tract is more challenging to treat. Eventually, the infection can spread into your blood, causing sepsis. Sepsis can be life threatening.
Additionally, UTIs in pregnant people can be dangerous for the pregnant person and baby.
If you are not pregnant and the nitrites are accompanied by symptoms, the treatment usually involves a course of antibiotics. Pregnant people will need a course of antibiotics whether or not they have symptoms.
The exact type of antibiotic you’re prescribed will depend on what kind of bacteria is in your urinary tract, your medical history, and whether you’re pregnant.
Proper treatment with antibiotics should resolve your symptoms within a day or two. Be sure to follow your doctor’s instructions and take the entire course of antibiotics. Not doing so can cause the infection to come back, and your doctor will have to prescribe a different type of antibiotic.
Drinking plenty of water to flush out the bacteria is also an important step in helping you recover more quickly.
Checking the urine without any symptoms is considered a screening test. Remember, nitrituria without other symptoms of a UTI may not indicate an infection.
People who are pregnant are often screened, as this may still be a sign of an infection that needs to be treated. If you have nitrituria and are having any other symptoms of a UTI, check with a healthcare professional.
When dealt with promptly, UTIs are easily treatable and usually resolve quickly in a couple of days.
If a urinalysis comes back positive for nitrites, see your doctor for further evaluation.
Seek emergency help if you have any of the following symptoms, as they could mean an infection has spread to your bladder or kidneys:
If you experience any of the above symptoms or any other symptoms of a UTI, you should seek a doctor’s care as soon as possible.