What is this?

Hey guys, my mom is getting blood work drawn tomorrow but I wanted to ask if you guys have heard of these symptoms before.

Btw she has gone to the dr before and they have told her she’s fine repeatedly. But she’s getting another blood work tmrw testing her for new things then before.

She’s overweight. But trying to eat healthy. She gets out of breath really fast, doing simple tasks. She also overheats every few days. To the point of a 99 degree fever. And this has been going on for months where she just has these heat flashes and takes her temp and it’s like 99.

I also know that she’s been really stressed recently. She’s in her mid 50s, could this be menopause?

Any idea what this could be? This has been an issue going on for months