Hello, Thanks for choosing HCM. I can understand your concern about your son. 1. To know about the relapse of nephrotic syndrome you need to have a 24 hour urinary protein done to know how much amount of protein is loosing in 24 hours and if it is more that one gram then your doctor will start treatment if your son is having symptoms along with protein loss. 2. Sodium restricted diet is suggested in child with nephrotic syndrome anyhow based upon the medical condition your doctor will suggest how much amount to give. So please avoid giving high sodium diet like the salt you are using. Please get back if you have more queries. Regards, Dr.Alekhya.