Hi My Brother Has Been Diagnozed With Nephritic Syndrom. And

Hi my brother has been diagnozed with nephritic syndrom. And high bloid pressure. He takes medication for his blood pressure but a medication he took for few days for his kidney problem caused hid blood sugar to go uo high somunder his dr advis ehe stopped it to get his blood sugar low. At this time he has dizziness and his legs are somewhat bloate dand getting stiff . What doesd he need to do at this time? Could his dizziness be because of high potassium?