Is drinking urine a survival strategy?
Reportedly a Chinese man trapped under a piece of ceiling managed to survive for more than six days after an earthquake in Sichuan, by drinking his own urine. (He says he used “what felt like leaves” to pool his liquid waste.) How long can one survive by drinking pee?
At best it is only a few days. A healthy person’s urine is made up of about 95% water and is generally sterile, so for a short while it’s quite safe to drink and does help to replenish lost water. But the other 5% of urine is made up of waste that your body did not want, including nitrogen, potassium, and calcium. When you drink your own pee, all the things that your body tried to expel comes right back into your system, and a lot of it ends up back in your kidneys to be processed again. After multiple cycles, the bad stuff in your urine will become very concentrated, and drinking it may cause symptoms like those brought on by total kidney failure. At that point, you’re doomed either way, from possible dehydration on the one hand or kidney malfunction on the other.
So it is probably a good idea to always carry a water filter with you just in case. If you do fall on hard times and have to drink the yellow liquid, at least you can filter all the bad stuff out, and make it just plain good old water. But remember even with the best filter you can not survive just by filtering your own urine indefinitely as the hydration cycle would eventually stop because, in addition to what a person pees out, the average person excretes about a pint of water a day through sweating and exhaling and that is much harder to recapture.