A urine pH test can tell your doctor how acidic or basic (alkaline) your urine is using a simple, painless urine test. Many diseases, your diet, and the medicines you take can affect how acidic or basic your urine is. For instance, results that are either too high or low can indicate the likelihood that your body will form kidney stones. If your urine is at an extreme on either the low or high end of pH levels, you can adjust your diet to reduce the likelihood painful kidney stones will form. In short, your urine pH is an indicator of your overall health and gives your doctor important clues as to what is going on in your body.
Kidney stones are small masses of minerals that can collect in the kidneys and cause pain as they prevent urine from passing through your kidneys and urinary system. Since these stones tend to form in a highly acidic or basic/alkaline environment, your physician may test your urine to determine the likelihood you will form kidney stones.
Because certain medications can make your urine more acidic, your physician also may order the urine pH test to determine if the medicine is making your urine too acidic.
The urine pH test can also be used to determine the best medication to prescribe when you have a urinary tract infection. For example, according to the National Institutes of Health, antibiotic medications such as streptomycin, neomycin, and kanamycin are most effective when your urine is alkaline (NIH, 2001).
Prior to testing, your physician may ask you to stop taking certain medications known to affect your urine pH. Examples of these drugs include:
- acetazolamide, used to treat glaucoma, epilepsy, and other disorders
- ammonium chloride, used in some cough medicines
- methenamine mandelate, used to treat urinary tract infections
- potassium citrate, used to treat gout and kidney stones
- sodium bicarbonate, used to treat heartburn and acid indigestion
- thiazide diuretics, used to treat high blood pressure and to reduce the risk of stroke and heart attacks
However, you should not make changes to your diet prior to the urine pH test unless directed to by your doctor. Because the foods you eat affect urine pH, you want the test to be as accurate as possible in predicting your typical urine pH level. This will help your doctor identify what the actual changes in your urine pH are caused by.
To get the best results, the urine pH test requires obtaining a clean-catch urine sample. This urine sample type is collected midstream, after you have cleaned the genital area around where you urinate. This reduces the likelihood that organisms and pathogens that could affect the sample will be in your urine.
You will be given a cup in which to urinate. Refrain from touching the inner portion of the cup (and letting anything but urine into the cup) to avoid contaminating the sample. Once you have urinated using the clean-catch method, give the urine cup to the appropriate medical staff. The sample must be taken to the laboratory as quickly as possible to ensure the most accurate results.
A laboratory will test your urine pH and return results.
7.0 is a neutral pH. The higher the number, the more basic it is. The lower the number, the more acidic your urine is. The average urine sample tests at about 6.0.
If your urine sample is lower, this could indicate an acidic environment for kidney stones or one of the following conditions:
- diabetic ketoacidosis
A higher-than-normal urine pH could indicate:
- gastric suctioning that takes away stomach acids
- kidney failure
- kidney tubular acidosis
- pyloric obstruction
- respiratory alkalosis
- urinary tract infection
Your diet also may determine how acidic or alkaline your urine is. For example, if you eat a diet low in meat and high in fruits and vegetables you are more likely to have alkaline urine (Welch, et al., 2008). Those who consume higher amounts of meat are more likely to have acidic urine. Your doctor may recommend some changes to your diet if your urine is too high or too low.
The urine pH test is not associated with any side effects because it mainly involves normal urination. You can typically resume your daily activities following the test.