Mel received the results of a urinalysis, and has been told she needs to come back in to speak with the doctor. All of the following were found in...

Mel received the results of a urinalysis, and has been told she needs to come back in to speak with the doctor. All of the following were found in her urine: glucose, potassium, sodium and urea. Which one is cause for concern? 

glucose

potassium

sodium