swollen lymph node in left groin?

[dancer4ever230]

I have a swollen lymph node in my left groin. It is a little bit bigger than the size of a semi-large pea. It seems to come and go. I do ballet so every day I must wear tight leotards. I also swim. I seems like if the elastic around the hip area on either the swimsuit or leotard is too tight, the lymph node gets swollen. Can that be a cause? When it is swollen it is also red and sometimes tender, sometimes not. I have also been struggling with a left ankle injury.

[dancer4ever230]

I have been struggling with an ankle injury from ballet for about a year. The swollen lymph node shows up every few weeks and it completely goes away in about a week. I am not sure when it first started. I had it and got medication for one about six years ago (I am almost 15 now). The doctor said that that one was a viral infection. My sister (12) got one and the doctor said that it would go away on its own (this was a few months ago).

[Mochadelicious]

It is unlikely in my opinion that a swollen node be caused by tight clothing.  However if it's already a swollen and the clothing continually rubs against it I can see how it would get red and tender.  

Lymph nodes swell due to an increase of white blood cells that are collecting there.  The usual reason they collect there is to fight off infections.  Have you been Ill lately?  When did you first notice the swollen lymph node?