hen with claw problem

Hello Jennyr265 and welcome to the forum. 
I am not that experienced but it sounds as if your hen may have bumblefoot.  If you type bumble foot into the search box in the top right hand corner you should come up with all kinds of info and some pictures that might help.
I'm sure someone more experienced will be along to advise you.  It might help if you could have a feel of the claw gently and see if it feels hot as well as swollen.
It may also be a good idea if you could take a picture and post it.
In the meantime good luck and keep us posted

Hi. Many thanks for your help. She seems a little better today. There are no cuts or abrasions anywhere on the claw - it's just very swollen. I'll keep an eye on it and visit the vet if necessary.Thank you!