# Tardigrades in your bloodstream **URL:** \ **Category:** Factual Questions\ **Created:** [January 15, 2020, 7:39pm UTC](https://boards.straightdope.com/t/tardigrades-in-your-bloodstream/846467 "2020-01-15T19:39:13Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![BwanaBob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bwanabob/32/2985_2.png) [@BwanaBob](https://boards.straightdope.com/u/BwanaBob)\ **Post date:** [January 15, 2020, 7:39pm UTC](https://boards.straightdope.com/t/tardigrades-in-your-bloodstream/846467/1 "2020-01-15T19:39:13Z")
It seems like it could happen quite easily; someone gets a cut or gash out in the wilderness and cleans the wound in a stream. Enter a tardigrade. Due to their large size (relative to bacteria) could they cause a blood clot or a stroke? Don’t need answer fast. ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [January 16, 2020, 10:50pm UTC](https://boards.straightdope.com/t/tardigrades-in-your-bloodstream/846467/2 "2020-01-16T22:50:22Z")
If blood was gushing out of a wound how exactly does the tardigrade, or anything else really, find it’s way into your bloodstream? Now if it was injected into your bloodstream with a syringe how long would it survive before your immune system neutralized it? ---
**Author:** ![Kimera757](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kimera757/32/3765_2.png) [@Kimera757](https://boards.straightdope.com/u/Kimera757)\ **Post date:** [January 17, 2020, 12:01am UTC](https://boards.straightdope.com/t/tardigrades-in-your-bloodstream/846467/3 "2020-01-17T00:01:35Z")
Why would it enter your bloodstream? And how? ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 17, 2020, 12:01am UTC](https://boards.straightdope.com/t/tardigrades-in-your-bloodstream/846467/4 "2020-01-17T00:01:35Z")
Tardigrades are huge compared to blood cells, so for a start, if one or more somehow found its way into your bloodstream, it could not traverse capillaries or the smallest venules and arterioles - so it could get stuck in a blood vessel. The body has some mechanisms that can deal with small obstructions by encysting the blockage and moving it out of the blood flow. I don’t know if this would work with an object the size of, and with the properties of a tardigrade, though. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [January 17, 2020, 12:41am UTC](https://boards.straightdope.com/t/tardigrades-in-your-bloodstream/846467/5 "2020-01-17T00:41:25Z")
Well, river blindness infects you when larvae 10 mm in length enter your bloodstream after you get bitten by a fly, so it’s not like big parasites cannot enter your system that way. For that particular disease they are nematodes rather than tardigrades, however. ---
**Author:** ![jasg](https://avatars.discourse-cdn.com/v4/letter/j/f0a364/32.png) [@jasg](https://boards.straightdope.com/u/jasg)\ **Post date:** [January 17, 2020, 1:20am UTC](https://boards.straightdope.com/t/tardigrades-in-your-bloodstream/846467/6 "2020-01-17T01:20:30Z")
Here you go… [25 of Your Most Frequently Asked Questions About Tardigrades Answered!](https://interestingengineering.com/25-of-your-most-frequently-asked-questions-about-tardigrades-answered). > [@](#): > > They cannot survive the trip through the human digestive tract since our stomach acid disintegrates the flesh of the tardigrade without much trouble, so eating one wouldn’t do any harm. So far, no one has reported a case where a disease or infection was introduced into the human body via tardigrade, and they aren’t parasitic. ---
**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:** [January 17, 2020, 7:31am UTC](https://boards.straightdope.com/t/tardigrades-in-your-bloodstream/846467/7 "2020-01-17T07:31:30Z")
Say what now? There’s something that kills tardigrades? ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [January 17, 2020, 10:06am UTC](https://boards.straightdope.com/t/tardigrades-in-your-bloodstream/846467/8 "2020-01-17T10:06:53Z")
… and it is INSIDE US??? :eek: ---
**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:** [January 17, 2020, 12:11pm UTC](https://boards.straightdope.com/t/tardigrades-in-your-bloodstream/846467/9 "2020-01-17T12:11:40Z")
> [@dolphinboy](#): > > If blood was gushing out of a wound how exactly does the tardigrade, or anything else really, find it’s way into your bloodstream? A penetrating injury with a contaminated object. This is also how things like tetanus and necrotizing fasciitis get started. > [@mangetout](#): > > The body has some mechanisms that can deal with small obstructions by encysting the blockage and moving it out of the blood flow. I don’t know if this would work with an object the size of, and with the properties of a tardigrade, though. IANAD, but ISTM that since a tardigrade is composed of biological material, your body ought to be able to break it down and get rid of it - but if it can’t, you’re right, I would expect your body to entomb it in a [granuloma.](https://en.wikipedia.org/wiki/Granuloma) > [@DPRK](#): > > Well, river blindness infects you when larvae 10 mm in length enter your bloodstream after you get bitten by a fly, so it’s not like big parasites cannot enter your system that way. There are stage(s) in the life cycle of [the river blindness parasite](https://en.wikipedia.org/wiki/Onchocerca_volvulus) in which the worms are anywhere from 2-70 cm long - but [the L3 juveniles that are passed from the black fly to the human host are only about 740 microns long and 19 microns wide.](https://www.ncbi.nlm.nih.gov/pubmed/9585936) ---
**Author:** ![Kimera757](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kimera757/32/3765_2.png) [@Kimera757](https://boards.straightdope.com/u/Kimera757)\ **Post date:** [January 17, 2020, 11:18pm UTC](https://boards.straightdope.com/t/tardigrades-in-your-bloodstream/846467/10 "2020-01-17T23:18:53Z")
> [@DPRK](#): > > Well, river blindness infects you when larvae 10 mm in length enter your bloodstream after you get bitten by a fly, so it’s not like big parasites cannot enter your system that way. For that particular disease they are nematodes rather than tardigrades, however. Tardigrades aren’t these worms, though. They have no reason to _want_ to be there. ---
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [January 17, 2020, 11:46pm UTC](https://boards.straightdope.com/t/tardigrades-in-your-bloodstream/846467/11 "2020-01-17T23:46:05Z")
Tardigrades basically eat by sucking the “juices” out of cells, don’t they? If so, I imagine they could do that to some of YOUR cells. Not on any kind of dangerous or noticeable scale, though. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [January 18, 2020, 5:43pm UTC](https://boards.straightdope.com/t/tardigrades-in-your-bloodstream/846467/12 "2020-01-18T17:43:51Z")
Since they aren’t “native” to the bodies blood system in any way, they are basically just another contaminant that might get into a suitably sized vein during a cut. They won’t thrive, reproduce, etc. Effectively a tiny bit of gravel. I’d be more afraid of the bacteria on them than the bug itself. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [January 19, 2020, 7:43pm UTC](https://boards.straightdope.com/t/tardigrades-in-your-bloodstream/846467/13 "2020-01-19T19:43:49Z")
> [@Mangetout](#): > > … > > The body has some mechanisms that can deal with small obstructions by encysting the blockage… “Encysting.” Cool word. Thanks. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [January 19, 2020, 8:41pm UTC](https://boards.straightdope.com/t/tardigrades-in-your-bloodstream/846467/14 "2020-01-19T20:41:35Z")
What did the monocyte say to the lymphocyte? I encyst.