# Leeches and the brain

**URL:** <https://boards.straightdope.com/t/leeches-and-the-brain/506850>\
**Category:** Factual Questions\
**Created:** [August 18, 2009, 3:55pm UTC](https://boards.straightdope.com/t/leeches-and-the-brain/506850 "2009-08-18T15:55:22Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![hyacinthinspring](https://avatars.discourse-cdn.com/v4/letter/h/53a042/32.png) [@hyacinthinspring](https://boards.straightdope.com/u/hyacinthinspring)\
**Post date:** [August 18, 2009, 3:55pm UTC](https://boards.straightdope.com/t/leeches-and-the-brain/506850/1 "2009-08-18T15:55:22Z")

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My 11 year old son asked the following question and I wondered if anyone knew the answer: If a leech enters the nose or ear openings, is it possible that it could reach the brain and possibly kill you by sucking out necessary blood flow?

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**Author:** ![Silophant](https://avatars.discourse-cdn.com/v4/letter/s/a698b9/32.png) [@Silophant](https://boards.straightdope.com/u/Silophant)\
**Post date:** [August 18, 2009, 5:43pm UTC](https://boards.straightdope.com/t/leeches-and-the-brain/506850/2 "2009-08-18T17:43:38Z")

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No. In either case, there’s a barrier between the brain and the outside. The ear has the eardrum, as well as all of the parts of the inner ear, and the nose [has a barrier as well.](http://faculty.washington.edu/chudler/brainnn.html)

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**Author:** ![pudytat72](https://avatars.discourse-cdn.com/v4/letter/p/ce7236/32.png) [@pudytat72](https://boards.straightdope.com/u/pudytat72)\
**Post date:** [August 18, 2009, 7:46pm UTC](https://boards.straightdope.com/t/leeches-and-the-brain/506850/3 "2009-08-18T19:46:49Z")

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Maybe what he heard about was the brain infection you can get when exposed to the ameba Naegleria. That enters the body through the nose and gets into the brain! Don’t get warm lake water up your nose!!

> **[CDC - Parasites](https://www.cdc.gov/parasites/)**
>
> A parasite is an organism that lives on or in a host and gets its food from or at the expense of its host. Parasites can cause disease in humans. Some parasitic diseases are easily treated and some are not. The burden of these diseases often rests...