My uncle is a patient with a ckd and the doctor prohibited him from drinking juices. why? what will juices do to him?

Juices and CKD: Your uncle may have two problems. One is that his CKD is far advanced and he may have problems with potassium (K) ingestion causing high K levels. K is found in citrus juices as well as tomato juice. Apple juice is low in K. The other problem is that he may have fluid accumulation that may be made worse by the volume of juice he ingests. I suspect that the K problem is the major reason.