We’ve all heard the survival stories of people stranded without water who have made the decision to drink their own urine. In this article I’ll do my best to address the age-old question: Is it a good idea to drink your own pee?
First, we have to understand the main function of our urinary system. If I could describe its function in one word it would be balance. The kidneys and accompanying team of tubes and membranes are in a constant state of “keeping the peace.” Ultimately, the urinary system filters and balances the blood. This involves maintaining an appropriate balance of water and all kinds of other things like sodium (salt), carbohydrates, potassium and glucose. During this filtering and osmotic process, toxins like uric acid are also found and flushed out with the excess of everything else we don’t need in what we call urine.
It’s important that our blood maintains a balance of everything it needs. Too much or too little of anything result in physiological consequences that we often refer to as “conditions” or “diseases.” Dehydration is one such condition.
Some of these levels can be altered simply by our diet. Below is a listing of sodium concentrations in what’s known as milliequivalent per liter. It’s the numbers that are important, not the word “milliequivalent,” so don’t get lost in the fancy chemistry words.
Sodium in mEq/L:
Human blood – 135-145 mEq/L
Seawater – 400+ mEq/L
Urine – 20-250 mEq/L
We’ve all heard that it’s not a good idea to drink seawater because of the salt levels. As you can see with the numbers above, the sodium dose is much higher in seawater than in human blood. When we drink seawater, our body has to balance out and expel all of that extra salt. It does this with urine, but when we consume a lot of salt (like with seawater), our body has to pull fresh water from somewhere else in our body to dilute the salty water we just drank. That’s just the way it works. Unfortunately, we’re not wired to magically pull out the salt. It must be mixed and diluted with water at a certain ratio in order to pass through our complex system. This results in us having to actually urinate more water out than we took in just to flush out the salt. Our mouths may be momentarily quenched by the wet liquid, but the long-term effects are increased dehydration and ultimately muscle and organ failure.
The same rule applies to urine. Besides ingesting traces of toxins and acids, urine also contains concentrations of salt (sodium) that may be higher than our body’s preferred average. If it does (and there is no way to tell by a field test) then the same rule applies to urine as it does to seawater. Furthermore, each time urine is reingested, the resulting new urine contains a higher level concentration of everything flushed from the time before. These increased doses of toxins and other unnecessary agents (including sodium) can cause additional problems on top of worsening dehydration.
The final answer
No, you should not drink your pee in a survival scenario. If you decide to throw the dice at your personal urine salt content, you may get away with it for a couple recycled flushes, but the adverse effects will quickly outweigh any hydration you might think you’re getting.
However, urine can be used in a solar or evaporative still that can collect the pure distilled H2O. This is perfectly fine to drink, but painfully slow.