My mom has been complaining about this pain she has in her groin. She is 79 years old. She was told by 1 doctor that it was a vein. And that was all. Since then her doctor retired. She has a new doctor and her new doctor said it might be a hernia. She doesn't think so. She says it feels like the vein is twisted. She has a lot of pain. Sometimes she can't move. She can't twist around. She can't do anything. Do you know what this might be?

Has her new doctor examined her or done any tests?

Yes, she wanted to her to see another doctor, for hernia. She didn't go. She said she thinks her first doctor was right when she told her it was a vein. My mom is not about to many tests.

Saying 'it's a vein' is meaningless. Yes, major vessels go down each leg right at the groin, the femoral arteries and veins. There is an opening for those vessels in the fascia (connective tissue) that holds the abdomen in, but sometimes a pouch of bowel escapes and goes down through that opening and down the inner thigh. That's a femoral hernia. Sometimes it bulges outward and sometimes it bulges internally and can't be detected.

Your mother may or may not have a hernia. I had the same pain 35 years ago and was operated on and didn't have one! 30 years later I found out that the pain was from my sacral nerves, that wrap around from the sacro-iliac to the front of the abdomen and branch out to the pubis, bladder, bowel, and that painful spot at the groin.

Good luck getting diagnosed. I had zero help from the medical profession for 35 years, and a chiropractor knew what it was immediately. That's ME, not her, of course.

Yes, she wanted to her to see another doctor, for hernia. She didn't go. She said she thinks her first doctor was right when she told her it was a vein. My mom is not about to many tests.
Been there, done that with both a stubborn mother and an even more stubborn mil. Of course, her retired doctor has nothing to do with her situation any longer, so she is going to have to continue to be in pain or maybe see another doctor (at least) for a checkup and maybe a test or two to figure out what this is and get it fixed.

She just can't diagnose herself and even if it is a twisted vein, this is a condition where veins become weak and the blood,pools causing the vein to twist. It still has to be seen to.

What kind of tests are there she should be tested for?

what kind of tests are there she should be tested for?
I'm guessing a sonogram for one test.

Sonogram and/or doppler studies would be first order.