Large Loop/Knot at the end of a dread

I don't know if this is common or not but at the end of one of my dreads is what looks like a large knot that I can't undo, will this come undone by itself or do I need to do something about it? I've attached a picture of it so you can see what I'm on about

updated by @edward-jeffrey: 02/05/15 10:12:49AM

why would u want to undo it?

its just a dread

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My new book Ban The Taboo Vol 1

I didn't know if it was normal or not, it just seemed odd to me that there was this big lump at the end of a fairly thin dread, but if that kind of stuff is just normal I'll leave it alone

I just read the Dreaducation page which covers this kind of thing, sorry, I should have had a more thorough look round the site before posting this