I have a hard lump in the palm of my hand. It's near the base. My palm and wrist are in pain

Hello Anon

Thank you for writing.

You will need to have this lump examined and/or tested to know what it is. You may have a very thick callus or a cyst. A ganglion cyst can come and go and sometimes need just a good slap to get rid of it, hence it's other name "bible cyst" where people used to use bibles to smack then cyst.
Since you are in pain, don't attempt this - see your doctor.
Best,
Susan