Good, that rules out a bunch of serious stuff a lot of people don’t think about.

Others have already given better advice, I’m just trying to brainstorm some of the less-likely possibilities.

Airplanes and firearms are the most common, but not the only form of lead exposure. Lead and heavy metal toxicity can take months of non-exposure to correct and wouldn’t show up on a normal blood test. It might be worth getting a blood test specifically for lead and other heavy metals like cadmium, palladium, and cobalt, especially if anyone you know works at a muffler shop or something.

The only other thing I can think of is maybe Radon, especially if you have a basement or other area in your house where air doesn’t circulate well. That wouldn’t necessarily show up on a blood test either. Radon test kits are cheap, but I think some of them require lab processing so look at for that if you decide to buy one.

Either way, I’m older than 32 and don’t have the same problems you describe. It’s definitely not “just getting older”.

Unfortunately, male doctors often don’t take women’s health issues seriously. I’m not sure how much you like and trust your current doctor, but a second opinion from another (possibly female) doctor may be a good idea.