Why do you get a "lump" in your throat when you need to cry?

Answer 1

I was just about to ask the same question. I decided to search for it first to see if anyone else asked. Well, I came across yours!

I found a website actually: http://www.madsci.org/posts/archives/mar97/855114309.An.r.html. It's a long answer. I just posted the last paragraph. Feel free to read it. : }
As an aside, the autonomic nervous system has two parts: sympathetic and parasympathetic. These function together much like the gas and brake pedals in a car. The sympathetic nervous system activate the heightened response to stress, and the parasympathetic nervous system reduces stress activity and promotes more recouperative activities. One of the chief purposes of the parasympathetic nervous system is to coordinate and run digestion, which includes swallowing. So the lump in your throat is caused by both the sympathetic and parasympathetic nerves of the throat being activated at the same time.

Here's another site!:
http://www.highlightskids.com/Science/ScienceQuestions/h1sciQlumpinThroat.asp
Crying occurs when the lacrimal glands of your eyes make tears faster than they can be carried away in the little tubes that drain into the back of your throat. Maybe before you really know you’re crying there’s an extra amount of tears going down these tubes to your throat. That would give some extra fluid in your throat and make you want to swallow. It might feel like a lump in your throat.

Answer 2

No one knows that you will cry, there is a KNOT that makes you think that you can stop. You can't. Cry. Girls will LUV you!

Answer 3

because.... it is letting you know u should cry.