A 15-year-old boy got in trouble at football practice. As punishment, his coach sentenced him to do 150 pushups over the weekend. His mother was assigned to monitor him and make sure he was compliant.
On Monday, he was unable to move his arms, which were in severe pain, and he noted that his urine was darker than normal. All of this concerned his mother, who brought him to the emergency department. This story of over-exercising, followed by excessive muscle pain and dark urine was worrisome to me. Quick blood and urine tests confirmed my suspicion. He had rhabdomyolysis.*
The excessive use of the muscles of his arms and shoulders caused enough muscle damage that a protein, myoglobin, was released from the muscles in such large amounts that it turned his urine dark. If not treated, that same protein could be toxic to the kidneys. This patient had to be admitted to the hospital to get pain medicine and IV fluids until his muscles healed and the myoglobin was cleared from his blood and urine.
Over-exercising is one of the more common causes of this condition. As far as I know, I have never seen it just from over-use of the upper extremities. Since your legs have so much more muscle mass than your arms, it is a lot more likely for this to develop after over-use of the legs. For example, we often see prisoners who do squats over and over until they develop rhabdomyolysis. They come in from jail with leg pain and dark urine and have to get admitted to the hospital.
I wonder if my patient’s coach will assign 150 pushups as behavior modification again.
*I posted a case previously about rhabdomyolysis. Please see Dancing with the Stars in a previous post.
Also, for more information, check out this Wikipedia article: https://en.wikipedia.org/wiki/Rhabdomyolysis