If it stays swollen all the time, Missy, it's essential to make sure it's not lymphedema, caused by blockage of the lymphatics on the left side. Your doc (and you) can check for swelling in the lymph nodes in the inguinal region (at the crease at the top of the thighs) and consider a pelvic ultrasound to be sure there isn't any sort of mass that might be causing lymphatic obstruction. I don't want to alarm you, but this needs to be checked out.

Is it painful?

Hello…

Yes, I also get it when I fly or there is extreme weather! Sending spoons… J🥄🥄🥄

If it is a clot or dvt it could be serious bc things are happening inside your body that you can not see. A clot can lead to heart attack or stroke. Please read and go get seen by a doctor asap.
https://www.nhs.uk/conditions/deep-vein-thrombo...

All the best. I’m praying that it isn’t serious.