Urine strips for making Diagnosis: Part 1

Urine strips are widely used in medicine to make a quick diagnosis of numerous medical disorders. The majority of these diagnostic reagent strips are designed only for human use and provide immediate useful information about health. Urine strips are frequently used by physicians and health care professionals in emergency room, outpatient clinics, nursing homes, doctor’s office and mobile ambulatory centers. The majority of urine strips are multipurpose and readily show color changes when an abnormality is identified. Most strips have gradations of color which allows one to judge the severity of the problem. For those who are not familiar with urine strips, the following information is readily available from urine strips:

Specific Gravity: Urine specific gravity is readily obtained from a strip but it only provides a clue to change in urine density. For more accurate testing, one needs to use a calibrated refractometer.

Urine pH is the most widely used property on a urine strip. The test strips are designed to measure pH change values to within 0.5 units. For the most part, urine pH values are okay for emergency use. Abnormal pH levels may be seen in the following conditions:

Alkaline urine

- Urinary tract infection
- Consuming a vegetarian diet
- Systemic alkalosis
- Bowel obstruction- pyloric stenosis
- Excessive vomiting
- Use of alkaline drugs

Acid urine

- Gout
- Fever
- Use of drugs like phenacetin
- Uric acid stones

The test strips are most accurate for pH in the range from 5-9. However, one has to remember that false negatives can occur because the solution may run over from the highly acidic protein test pad to the urine pH pad. Thus, it is important to hold the strip horizontally when evaluating urine for pH. Whenever there is doubt about urine pH, a pH meter can be used to verify your results.