Activities on application

I was pre-nursing in undergrad before switching to public health. During this time, I got certified as a CNA, spent a few hundred hours interning and volunteering in hospitals and participating in other clinical experiences. I had some tough stuff occur personally my senior year and took a year off after college to travel. I’m now a year and a half out of undergrad, completing my MS but realizing I probably need to take a few more basic science classes and physics before I apply. I am hoping to apply to med school this coming application round, but by then it will already be 2 years since I graduated from my undergrad. On the med school applications people talk about using experiences/activities only in your undergrad. Can I include all my nursing and volunteer work that will be 5 years old as well as the stuff I’ve been doing recently or can I only include the stuff I’ve done in the 4 years leading up to my application?

Any input is appreciated, thanks!

Anything you did starting freshman year of your university coursework counts.