Patient information: Split urine collection for orthostatic proteinuria

INTRODUCTION

A split urine test is a method to determine whether the protein discovered in your urine is due to a condition called orthostatic proteinuria. For reasons that are not well understood, this causes a person to have protein into their urine when they are standing or sitting but not while they are lying down. The split urine test is one way to determine if this condition is present.

Orthostatic proteinuria is a harmless condition that is not uncommon in young people. Generally, no further testing or treatment are necessary after diagnosis. (See "Patient information: Protein in the urine (proteinuria)".)

EQUIPMENT

The test requires that you collect all of your urine for 24 hours. Pick a day when this would be convenient. Males may want to buy an inexpensive urinal for easy collection; females may buy an inexpensive basin urinal (urine hat).

You will also need two jugs and a funnel. Two half gallon plastic jugs (eg, milk jugs), thoroughly rinsed, are adequate if jugs are not provided. Label the two jugs: (1) Daytime urine and (2) Nighttime urine.

PROCEDURE

Perform the following steps on the day that you are going to collect the urine.

• When you first get up, discard the first morning urine.
• For the rest of the day, collect all of the urine each time you void. Put this urine into the Daytime urine jug. Continue to perform normal daily activities.
• In the evening, lie down two hours before you go to sleep. Just before sleeping, void for the last time and add this urine to the Daytime jug. Lying down for two hours avoids contamination of the nighttime collection with urine formed during the day.
• The following morning (approximately eight hours after going to sleep) collect the first morning urine and put in the Nighttime urine jug.
• Take the two jugs to the laboratory.

The healthcare provider's office will notify you when the results are available.

WHERE TO GET MORE INFORMATION

Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two people are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.

This discussion will be updated as needed every four months on our web site (www.uptodate.com/patients). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.

Some of the most pertinent include:

Patient Level Information:
Patient information: Protein in the urine (proteinuria)

Professional Level Information:
Evaluation of isolated proteinuria in adults
Measurement of urinary protein excretion
Orthostatic or postural proteinuria
Overview of heavy proteinuria and the nephrotic syndrome

A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable.

• National Library of Medicine

      (www.nlm.nih.gov/medlineplus/healthtopics.html)

• National Institute of Diabetes & Digestive & Kidney Diseases

     (www.niddk.nih.gov/)