The pH measures how acidic or alkaline a person’s urine is. Ideally, the pH of urine should be around 6.0 to 7.5, but a wider range is usually acceptable.

Doctors often test the urine pH and carry out other diagnostic tests when someone has symptoms possibly relating to a urinary tract or kidney issue.

This article examines typical pH ranges for urine, what different pH ranges may indicate, and more.

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Urine consists of water, salts, and waste products from the kidneys. The balance of these compounds can affect urine’s acidity levels, which specialists measure in pH.

The common value for urine pH is 5.5–7.5 for most people, but any value within the 4.5–8.0 range is generally not a cause for concern.

The pH scale runs from 1 to 14, with 1 being the most acidic and 14 the most alkaline.

However, different laboratories may have different ranges for typical pH levels. The laboratory report will explain the typical and atypical levels for the specific laboratory. A doctor will usually explain these results to the person.

Urine pH that falls outside the expected range can be a sign of an infection or a problem with kidney function. It could also be a sign that therapy to change the urine pH is working.

Another major factor affecting urine pH is the food a person eats. A doctor may ask a person about their typical nutrition before evaluating their urine pH results, as that may affect the typical results for that person.

A doctor will assess a person’s urine pH according to the reason for doing the urinalysis.

Many factors can affect urine pH, which can vary greatly, so a doctor cannot diagnose a medical condition based on pH alone. For instance, a high pH could signal a urinary tract infection (UTI) or a different kind of infection.

A doctor may consider urine pH along with other symptoms to make a diagnosis. They may also order a urine pH test to study the effectiveness of kidney stone treatments.

Carbonic anhydrase inhibitor medications, such as acetazolamide (Diamox), aim to make urine more alkaline, so a doctor may take more than one sample to see whether the pH is changing.

A doctor may ask for a single urine sample, or a 24-hour urine test, where a person collects their urine several times over the course of one day.

A person will collect a one-time urine sample using the “clean-catch” method to prevent bacteria from entering the sample by catching the urine midstream.

This method requires a person to clean their genital area, release a small amount of urine, and collect about 2 ounces or 60 milliliters of urine for pH testing.

Both one-time samples and 24-hour urine samples undergo urinalysis.

A urinalysis has three major components:

  • Physical and visual exam: When a doctor or laboratory technician examines the urine, they will look at its color, whether foreign material such as blood is present in the urine, and whether the urine appears foamy.
  • Chemical dipstick test: A dipstick test involves holding a piece of specially treated paper called litmus paper in a urine sample. The dipstick will change color to show how acidic or alkaline the urine is. It may also change color if other substances, such as glucose, white blood cells, bilirubin, or proteins, are present in the urine.
  • Microscopic exam: A laboratory technician will examine a small amount of urine under a microscope to look for particles, such as red blood cells, crystals, or white blood cells. These are not usually present in the urine and can indicate an underlying medical condition.

A urine pH test does not cause side effects. A person will urinate as they typically would to provide the sample, although the doctor may ask for the first urine of the day or a midstream sample.

For a 24-hour sample, they may offer additional instructions, such as fully emptying the bladder at the beginning of the collection day.

  • kidney stones
  • (UTIs
  • kidney-related disorders

A person can also have a higher urine pH due to prolonged vomiting. This rids the body of stomach acid, which can make body fluids more basic.

Acidic urine can also create an environment where kidney stones can form.

If a person has low urine pH, meaning that it is more acidic, it might indicate a medical condition, such as:

Taking certain medications can also make a person’s urine pH more basic or acidic.

The acidity or alkalinity of urine can help a doctor diagnose medical conditions. Doctors can test urine pH using a litmus paper test.

A doctor can perform a urine pH test as part of a larger urinalysis test or specifically test urine pH.

High and low pH levels can indicate problems with a person’s kidneys, such as an environment that could help kidney stones develop.

Is a high urine pH dangerous?

High urine pH is not dangerous on its own. However, it can be a sign of a condition that may need treatment, such as a UTI or kidney stones.

What does a high pH in urine mean?

High urine pH means the urine is alkaline or basic with a pH between 7–14. A doctor will assess high pH along with other indicators to determine if someone has an infection or other medical condition.

What causes elevated pH in urine?

A UTI and kidney stones are two possible causes of an elevated pH, but there are others. Certain medications, such as acetazolamide (Diamox), can also increase urine pH.

Should urine be acidic or alkaline to prevent UTI?

Acidic urine may help to prevent certain UTIs. Urine is usually slightly acidic, with a pH range of 4.0 to 8.0. It is more difficult for bacteria to survive in urine with a pH less than 5.0.

However, even if the urine pH is low, certain urease-producing bacteria, such as Staphylococcus and Proteus types, can increase the urine pH to improve their survival.

What pH of urine indicates a UTI?

A urine pH of 8.5–9 may indicate a UTI. If you have a UTI, your urine may be acidic or alkaline.

The urine is more likely to be alkaline with a pH of 8.5–9 when the infection is due to certain urease-producing bacteria.

However, it is important to note that a UTI may still be present if your urine is acidic. A doctor will consider a person’s symptoms and all values in the urinalysis to determine whether they have a UTI.