Drinking urine or urophagia is a practice dating back to ancient man. In some ancient culture the rich people used to take the expensive herbs that have magical effects in their body. Part of that herbs don’t metabolize completely so the poor one use to collect the urine of rich one to enjoy the same type of magical effect. Even the poor one used to collect their own urine to enjoy the full effects of those herbs.
Reasons for drinking urine include attempted survival, ceremonial purposes, sexual practices, and alternative medicine. Medical reasons include teeth whitening, fertility treatments, hormone therapy, and to prevent or treat cancer, arthritis, allergies and other diseases. So many research are going on to support the beneficial effect of urine.
In most of the TV shows you might have seen drinking urine as a part of survival technique so how much it is safe. A healthy person’s urine is about 95 percent water and sterile (no any pathogens), so in the short term it’s safe to drink and does replenish lost water. But the other 5 percent of urine comprises a diverse collection of waste products, including nitrogen, potassium, and calcium so if u drink too much of these then can cause problem. As you are putting back the waste product in your body that the kidney should excrete and may be that can lead to the situation similar to the kidney failure in long term.
Although drinking any liquid, including urine, may relieve the immediate sensation of thirst, because there are receptors present in your esophagus and stomach that send message to brain as fluid is coming but if it is concentrated urine later the sodium and other minerals actually make you more dehydrated, in much the same way as drinking sea water. Some people did drink their own urine in extreme survival situations and lived to tell the tale, but even the U.S. military advises personnel against it.
However in case of a survival situation, you can use your urine as a source of water, by distilling it.