Orthostatic Information and Courses from MediaLab, Inc.

Patients over the age of 60 have a greater chance of having protein in their urine. Occult malignancies and glomerulonephritis, that occur more frequently in the elderly, may be signaled by the presence of proteinuria. Orthostatic proteinuria is a condition seen most often in young adults. The condition may be caused by pressure on the renal nerve. When this condition is suspected, two urine specimens are tested. One specimen is collected upon arising in the morning, and the second is collected several hours later. When this condition is present, the first morning specimen, after the patient has been in a supine position, will be negative for protein. The second specimen, taken after the patient has been upright for several hours, would be positive for protein.

Severe proteinuria (greater than 3.5 g/day) is characteristically seen in patients with glomerulonephritis, lupus nephritis, lipoid nephrosis, and severe venous congestion of the kidney. Moderate proteinuria (0.5-3.5g/day) is seen in nephrosclerosis, multiple myeloma, diabetes nephropathy, malignant hypertension, and pyelonephritis with hypertension. Mild proteinuria (less than 0.5 g/day) may be seen with polycystic kidneys, chronic pyelonephritis, benign orthostatic proteinuria, and some renal tubular diseases. Transient proteinuria can also be due to physiologic conditions such as stress, exercise, cold exposure, and fever, in the absence of renal disease.