Ph2hur
A 2-hour urine pH test measures the acidity or alkalinity of your urine over a 2-hour collection period to help evaluate kidney function and detect certain metabolic disorders.
{"Urine pH indicates how acidic or alkaline your urine is on a scale of 1-14","Normal urine pH typically ranges from 4.5 to 8.0","This test helps diagnose kidney stones, urinary tract infections, and metabolic conditions","Diet, medications, and certain health conditions can affect your urine pH results","A 2-hour collection provides a more accurate picture than a single sample"}
Key facts at a glance
- LOINC
- 53651-6
- Short code
- pH2HU
- Synonyms
- pH 2h Ur
- Category
- chemistry
- Sample
- serum
- Container
- Clean sterile urine container or urine collection cup
- Units
- not specified
- Ref low
- 4.5
- Ref high
- 8
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Potentiometry using pH electrode or colorimetric dipstick method
- CPT
- 81001
- SNOMED
- 271710005
- Specimen volume
- Minimum 10 mL, preferred 20-50 mL for adequate analysis
- Stability
- Room temperature: 2-4 hours; Refrigerated (2-8°C): 24-48 hours; Frozen (-20°C): not recommended as pH may change upon thawing
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 1–4 hours
- Order
- routine
What is this test?
The 2-hour urine pH test measures the hydrogen ion concentration in your urine over a 2-hour period. pH is a scale from 1 to 14 that indicates how acidic (low pH) or alkaline (high pH) a substance is. A pH of 7 is considered neutral. This test requires you to collect all urine produced during a 2-hour period.
Why is it done?
Your healthcare provider may order this test to: evaluate kidney function, diagnose or monitor urinary tract infections, detect kidney stones, assess metabolic disorders, monitor certain medication effects, or investigate symptoms like frequent urination, pain, or blood in urine.
How to prepare
Before the test, inform your doctor about all medications, vitamins, and supplements you take. You may need to avoid certain foods or medications that could affect results. Typically, you should fast overnight before the test. Your doctor will provide specific instructions on how to collect the urine properly over the 2-hour period.
Understanding your results
Normal urine pH typically ranges from 4.5 to 8.0, with most healthy individuals having urine pH between 5.5 and 7.0. A pH below 5.5 suggests acidic urine, which may indicate conditions like diabetic ketoacidosis, diarrhea, or a meat-rich diet. A pH above 8.0 suggests alkaline urine, which may be due to urinary tract infections, kidney disease, or a vegetarian diet.
Reference range
4.5-8.0not specified
No fasting required; collect midstream clean-catch urine over exactly 2 hours per lab protocol
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Does diet affect urine pH?
Can medications affect my urine pH results?
Is the 2-hour urine collection painful?
What happens if my urine pH is abnormal?
Sources
- 1
- 2Mayo Clinic - UrinalysisSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy