As summer is winding down it is time for the last minute rush of sports physicals for high school. Brett has been my patient since he was born 16 years ago, and has grown into a fine young man. He will be a junior in high school, having excelled both in the classroom and in athletics. He plays football and baseball, and is good enough to be considered for a scholarship in baseball.
As I reviewed his chart I mentioned to his mom that he has only been in for yearly physicals over the past three years. Both Brett and his mom simultaneously “knocked on wood” stating that he has been in perfect health and has not missed a day of high school.
His growth, blood pressure, vision and examination were completely normal. He was pleased with the mention that the immunizations were current so that he would not need any shots. As I started to fill out his sports participation form there was a knock at the door. The nurse handed me the results of the urinalysis from the specimen he gave when he arrived. I was surprised to see that there was 2+ protein in the urine, although everything else was normal.
Protein in the urine can be a sign of a serious kidney disorder and is not something to be taken lightly. I was not overly concerned because Brett was in such good shape, had no evidence of edema or swelling and had a normal blood pressure. I could see the panic in mom’s face as we discussed what this could mean, and what we needed to do to resolve it. She apologized for becoming so upset. She told me about an uncle that had some form of glomerulonephritis and had to have dialysis.
To allay any of her fears I told her that I thought Brett had a benign condition called postural—or orthostatic proteinuria. This is a common condition that is seen in older children and teens who are usually tall and thin, exactly like Brett. It is a benign condition that requires no treatment, and a condition in which the kidneys are completely normal. The exact cause of postural proteinuria is not known but it most likely is a positional phenomena occurring only when one is standing and not laying down. Orthostatic refers to standing; hence the name orthostatic proteinuria.
I went on to tell them that the diagnosis of this condition is a simple one. I gave them two containers in which to collect urine specimens. I told Brett to urinate before he went to bed, but to flush that voiding. Then when he awoke the next morning he was to collect that specimen before he even got out of bed. I had him label that specimen night urine. He was to collect the rest of the urine throughout the entire day until he went to bed that night. He was to label this specimen day urine. I asked them to drop off the urines the following morning and we would have our answer right away.
Needless to say, he brought in the urines within two days, as mom couldn’t wait to get the results. She sheepishly informed me that she looked online about proteinuria and was a basket case because of all the things she thought it could be. I was relieved to find that the night urine had absolutely NO protein. The day urine had 2+ protein, thus confirming the diagnosis of postural proteinuria. They were equally relieved when I told them that we were done and they need not give this a second thought from this point on. But I wanted Brett to remember that he had been worked up for postural proteinuria in the event that he was ever told that he had protein in his urine in the future.