Can you survive by drinking your own urine?

In extreme situations, such as being lost in the desert or adrift on the ocean, hydration is particularly difficult. When you are thirsty in an environment where fresh water is difficult to obtain, one of the last resorts is to drink your own urine. However, Matthew Barton, a senior lecturer at the School of Nursing at Griffith University, and Michael Todorovic, an associate professor at Bond University's School of Medicine, explain whether drinking your own urine is really the right thing to do as a survival technique.

If you get lost in the bush, can you really survive by drinking your own pee?
https://theconversation.com/if-you-get-lost-in-the-bush-can-you-really-survive-by-drinking-your-own-pee-269086

In his survival show on the Discovery Channel, adventurer Bear Grylls demonstrates how to stay hydrated in extreme situations, including squeezing water out of elephant dung, sipping camel intestines, and drinking yak eye juice.

Grylls has actually been known to drink his own urine. 'Urinating on the ground is a waste of bodily fluids. Drinking your own urine is safe,' he said, before sipping it and grimacing, describing it as 'warm and salty.'

Bear Grylls drinks his own urine (Kimberlies, Australia) - YouTube


Body fluids make up about 60% of our body weight. To maintain the proper balance of substances in our internal environment, our kidneys constantly filter about 180 liters of plasma every day. However, our kidneys reabsorb about 99% of the urine they filter, so we don't excrete as much as 180 liters of urine.

The content of urine varies depending on several factors, including hydration status, metabolic activity, and diet, but it is approximately 95% water, with the remainder made up of urea, creatinine , salts, and protein.

While urine normally provides some hydration, extreme conditions like Grylls' can cause the body to lose fluids. For example, we lose about 450ml of water per day through sweating and about 300ml per day through breath vapor. In hot and humid environments, these amounts increase significantly.

As a result, your kidneys hold on to precious water and the waste products become even more concentrated, ultimately making your urine highly toxic. So if you drink urine in a survival situation, you're ingesting high concentrations of urea and other waste products that your body is clearly trying to eliminate.

Drinking urine with a high concentration of waste products, or if kidney function is impaired, can cause urea and other metabolic waste products to build up in the body and become toxic, particularly to cells of the nervous system, leading to symptoms such as vomiting, muscle spasms, itching, and loss of consciousness.

There's also a hygiene issue. While urine leaving the kidneys is likely sterile, the same cannot be said for the bladder and urethra. Our bodies are rich in resident bacteria that help keep us healthy and function on a daily basis. Drinking urine reintroduces these bacteria into parts of the body where they shouldn't live, primarily the digestive tract.

In healthy individuals, stomach acid kills many of these bacteria, but in survival situations where the intestinal wall is damaged by dehydration, heatstroke, or poor nutrition, these bacteria are at greater risk of entering the bloodstream.

So, even in extreme circumstances, drinking your own urine is not recommended and could even be life-threatening. 'If you're lost in the bush, don't resort to drinking your own urine. It's the same as drinking urine from a garbage can,' Burton and Todorovic wrote.