# How sterile is urine really? **URL:** \ **Category:** Factual Questions\ **Created:** [April 26, 2015, 2:29am UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551 "2015-04-26T02:29:55Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![sara20](https://avatars.discourse-cdn.com/v4/letter/s/e79b87/32.png) [@sara20](https://boards.straightdope.com/u/sara20)\ **Post date:** [April 26, 2015, 2:29am UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/1 "2015-04-26T02:29:55Z")
I have read that fresh urine is sterile, but how sterile is stale urine? For example if someone was to put fresh urine in a jar for a couple days would it start to grow harmful bacteria? ---
**Author:** ![Alley\_Dweller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alley_dweller/32/430_2.png) [@Alley\_Dweller](https://boards.straightdope.com/u/Alley_Dweller)\ **Post date:** [April 26, 2015, 2:37am UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/2 "2015-04-26T02:37:19Z")
> [@sara20](#): > > I have read that fresh urine is sterile, but how sterile is stale urine? For example if someone was to put fresh urine in a jar for a couple days would it start to grow harmful bacteria? Is the jar sterile? Is the lid sterile? Was the urine collected under sterile conditions? Did the urine have to make its way through a non-sterile foreskin, for example? ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [April 26, 2015, 3:01am UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/3 "2015-04-26T03:01:02Z")
1. The anterior urethra is not sterile and grows several sorts of bacteria common to skin and mucous membranes. 2. Urine is actually [not quite sterile](http://www.sciencedaily.com/releases/2015/03/150330134507.htm) after all. > [@](#): > > “Clinicians previously equated the presence of bacteria in urine to infections. The discovery of bacteria in the urine of healthy females provides an opportunity to advance our understanding of bladder health and disease,” said Alan Wolfe, PhD, lead author and professor in the Department of Microbiology & Immunology, SSOM. “Physicians and researchers must reassess their assumptions surrounding the cause of lower urinary tract disorders and consider new approaches to prevent and treat these debilitating health issues.” > > Stritch researchers evaluated urine specimens collected directly from the bladder through an aspiration or a catheter to avoid contamination. These specimens were analyzed using an expanded quantitative urine culture (EQUC) technique that identifies bacteria not detectable by the standard urine culture techniques typically used to diagnose urinary tract syndromes. This study also used 16S rDNA sequencing to classify bacterial DNA. > > “While traditional urine cultures have been the gold standard to identify urine disorders in the past, they do not detect most bacteria and have limited utility as a result,” Dr. Wolfe said. “They are not as comprehensive as the testing techniques used in this study.” Appreciate however that freshwater out of a lake isn’t sterile either and actually has total bacteria counts as high or higher as that in urine during an infection. ---
**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\ **Post date:** [April 26, 2015, 3:48am UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/4 "2015-04-26T03:48:30Z")
Sterile enough to drink…not sterile enough to put in your veins. ---
**Author:** ![sara20](https://avatars.discourse-cdn.com/v4/letter/s/e79b87/32.png) [@sara20](https://boards.straightdope.com/u/sara20)\ **Post date:** [April 26, 2015, 9:31am UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/5 "2015-04-26T09:31:00Z")
How come if urine is left to sit in a sterile container for several days it starts to smell bad, is this the result of bacteria growing? I have also seen crystals form at the bottom of the container, what are these? ---
**Author:** ![grude](https://avatars.discourse-cdn.com/v4/letter/g/e47774/32.png) [@grude](https://boards.straightdope.com/u/grude)\ **Post date:** [April 26, 2015, 9:33am UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/6 "2015-04-26T09:33:51Z")
> [@sara20](#): > > How come if urine is left to sit in a sterile container for several days it starts to smell bad, is this the result of bacteria growing? I have also seen crystals form at the bottom of the container, what are these? There really isn’t anything in a healthy person’s urine that would lead to a large growth of bacteria, various health conditions can lead to say sugar in the urine though. ---
**Author:** ![sara20](https://avatars.discourse-cdn.com/v4/letter/s/e79b87/32.png) [@sara20](https://boards.straightdope.com/u/sara20)\ **Post date:** [April 26, 2015, 9:39am UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/7 "2015-04-26T09:39:33Z")
> [@grude](#): > > There really isn’t anything in a healthy person’s urine that would lead to a large growth of bacteria, various health conditions can lead to say sugar in the urine though. Why does it smell bad then? ---
**Author:** ![grude](https://avatars.discourse-cdn.com/v4/letter/g/e47774/32.png) [@grude](https://boards.straightdope.com/u/grude)\ **Post date:** [April 26, 2015, 9:51am UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/8 "2015-04-26T09:51:19Z")
> [@sara20](#): > > Why does it smell bad then? The urea which is normal in urine turns into ammonia. Bad odor by itself is not necessarily an indication of bacterial activity. ---
**Author:** ![Kobal2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kobal2/32/20_2.png) [@Kobal2](https://boards.straightdope.com/u/Kobal2)\ **Post date:** [April 26, 2015, 10:33am UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/9 "2015-04-26T10:33:21Z")
> [@sara20](#): > > I have also seen crystals form at the bottom of the container, what are these? [Urea](http://en.wikipedia.org/wiki/Urea). It also explains the smell long-term, as with time it decays back into ammonia. Ammonia stinks, and is also toxic and corrosive in high concentration, which is why your body wants to store it in urea and piss it out before the decay happens. ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [April 26, 2015, 12:37pm UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/10 "2015-04-26T12:37:11Z")
> [@sara20](#): > > How come if urine is left to sit in a sterile container for several days it starts to smell bad, is this the result of bacteria growing? **I have also seen crystals form at the bottom of the container** , what are these? Are we all just going to let this go like this is a totally normal sentence? ---
**Author:** ![oz0ne](https://avatars.discourse-cdn.com/v4/letter/o/9fc348/32.png) [@oz0ne](https://boards.straightdope.com/u/oz0ne)\ **Post date:** [April 26, 2015, 1:45pm UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/11 "2015-04-26T13:45:33Z")
> [@Smeghead](#): > > Are we all just going to let this go like this is a totally normal sentence? I was going to ask, but I got distracted googling piss crystals. ---
**Author:** ![Kobal2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kobal2/32/20_2.png) [@Kobal2](https://boards.straightdope.com/u/Kobal2)\ **Post date:** [April 26, 2015, 7:37pm UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/12 "2015-04-26T19:37:28Z")
> [@Smeghead](#): > > Are we all just going to let this go like this is a totally normal sentence? For science, boy. Science ! I’m sure they all told \*\*sara \*\*she was mad, MAD they said, but she’ll show them all, oh yes… ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [April 26, 2015, 8:47pm UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/13 "2015-04-26T20:47:33Z")
Have you tried pan-frying it, perhaps? ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [April 26, 2015, 11:12pm UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/14 "2015-04-26T23:12:30Z")
> [@Kobal2](#): > > For science, boy. Science ! I’m sure they all told \*\*sara \*\*she was mad, MAD they said, but she’ll show them all, oh yes… One need not be a mad scientist to collect urine in jars. It might be that our OP has discovered the wonders of [urine therapy](http://www.shirleys-wellness-cafe.com/UT/Urine.aspx). Most aficionados of this traditional healing method seem to advocate consumption of the fresh article, but there remains the problem of having a backup supply for when guests drop by unexpectedly… ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [April 28, 2015, 1:00am UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/15 "2015-04-28T01:00:59Z")
> [@Jackmannii](#): > > It might be that our OP has discovered the wonders of [urine therapy](http://www.shirleys-wellness-cafe.com/UT/Urine.aspx). > > Most aficionados of this traditional healing method seem to advocate consumption of the fresh article, but there remains the problem of having a backup supply for when guests drop by unexpectedly… OTOH, **Cecil** Hisself [says of Urine Therapy (UT)](http://www.straightdope.com/columns/read/1043/why-are-men-supposed-to-wash-their-hands-after-urination): > [@](#): > > On the other hand, Asplin said, UT isn’t likely to do you much good either. Listen to your body. Your body is saying, “I just got rid of this stuff, granola-brain. Are you nuts?” > > But if you want to try it, be my guest. Just don’t eat any asparagus first. So who ya gonna believe, **Cecil** or this Shirley Lipschutz-Robinson character? As a bonus, the above comment also addresses an important issue for when guests drop by, at least if you’re the guest. ---
**Author:** ![BubbaDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bubbadog/32/333_2.png) [@BubbaDog](https://boards.straightdope.com/u/BubbaDog)\ **Post date:** [April 28, 2015, 1:28pm UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/16 "2015-04-28T13:28:25Z")
> [@oz0ne](#): > > I was going to ask, but I got distracted googling piss crystals. Be advised that name is already taken! Bubbadog Lead Guitar and Vocals The Googling Piss Crystals ---
**Author:** ![Elemenopy](https://avatars.discourse-cdn.com/v4/letter/e/b5e925/32.png) [@Elemenopy](https://boards.straightdope.com/u/Elemenopy)\ **Post date:** [April 28, 2015, 2:44pm UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/17 "2015-04-28T14:44:48Z")
> [@Smeghead](#): > > Are we all just going to let this go like this is a totally normal sentence? I once was asked to do a 24 hr urine collection to check for…I forget. Cortisol or sugar, probably. Dr. changed his mind but I forgot the jug in the fridge for a few days. Well, I had to look, duh. It was pretty nasty. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [April 28, 2015, 2:59pm UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/18 "2015-04-28T14:59:55Z")
> [@DSeid](#): > > > [@](#): > > > > “While traditional urine cultures have been the gold standard…” It was difficult not to laugh while reading this. ---
**Author:** ![lazybratsche](https://avatars.discourse-cdn.com/v4/letter/l/ba8739/32.png) [@lazybratsche](https://boards.straightdope.com/u/lazybratsche)\ **Post date:** [April 28, 2015, 3:40pm UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/19 "2015-04-28T15:40:04Z")
> [@DSeid](#): > > 1. The anterior urethra is not sterile and grows several sorts of bacteria common to skin and mucous membranes. > > 2. Urine is actually [not quite sterile](http://www.sciencedaily.com/releases/2015/03/150330134507.htm) after all. > > Appreciate however that freshwater out of a lake isn’t sterile either and actually has total bacteria counts as high or higher as that in urine during an infection. I recall a talk at a conference discussing bacteria that infect bladder epithelium (the layer of cells lining the inside of your bladder). Since your has to expand and contract dramatically, it also changes surface area. When your bladder contracts, epithelial cells deal with this by turning large portions of the cell membrane into intracellular vesicles. The membranes are returned back to the cell surface as the bladder expands. This whole membrane recycling process provides an environment for bacteria to hide. The bacteria attach to the epithelium and hitch a ride inside the cells with the extra cell membrane is gathered up and stored internally. Once inside the cells, the bacteria manipulate the membrane recycling process so that they stay inside the cells even when the bladder is expanded. (The talk was primarily about the molecular cell biology of membrane recycling and how bacteria manipulate the process.) I believe these bacteria are responsible for common types of recurring infections. They’ll be dormant, living peacefully in the bladder epithelium and never showing up in a urine culture, but occasionally they’ll cause an outbreak. After the outbreak ends on its own, perhaps thought to be “cured” by ineffective antibiotics, the bacteria remain in the bladder epithelium and will cause another outbreak in the future. In the bigger picture, it’s another example of how many different places thought to be sterile are actually full of bacteria that were invisible because they didn’t grow on a petri dish. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [April 28, 2015, 9:38pm UTC](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551/20 "2015-04-28T21:38:38Z")
The context in which I heard about the relative sterility of urine was its use in the Vietnam war to clean surgical tools, when there was no bottled water available. It’s not that the urine was sterile, it’s just a lot better than anything else available in the jungle. Meanwhile, Bob’s bleeding out. Why does urine smell bad? Most likely, for the same reason that feces and rotten meat smell bad: because we live longer if we avoid the stuff. It certainly doesn’t smell bad to my dog. [Next page](https://boards.straightdope.com/t/how-sterile-is-urine-really/718551.md?page=2)