Posted by: @schmed

left strut makes a rattle sound even going over a flat freeway. Can they possible come loose or is it just worn out. It's definitely a rattle.

Although nuts and bolts are used to secure a strut, a strut mount or the strut itself is more often the culprit. You need to have a mechanic check the struts.

Posted by: @schmed

Meaning replace the whole strut? The car does have 110,000 on it and they're recommended to be changed a little before that. Thanks much!

"They" sounds like a dealer, ignore them. A good local mechanic can check the strut and the strut mount. If it's only the strut mount that's bad, have him replace the mount. If the strut itself is bad, you'll need to replace both front struts. Always replace struts in pairs.

Posted by: @schmed

2014 Honda CR-V - 110,000 miles - left strut makes a rattle sound even going over a flat freeway. Can they possible come loose or is it just worn out. It's definitely a rattle.

Your strut mounts are probably shot. They're plastic, and, if you drive in pothole prone areas, they're subject to a lot of wear and tear. The whole car is pressing down on the shock and strut mounts. If you drive on rough roads constantly, your strut mounts will wear out more quickly as a result. They're only designed to withstand so many up and downs, and potholes quickly hasten their demise. The entire strut and strut mount needs to be replaced, and do it to both sides. Typically, strut mounts break as you remove pressure from the suspension and start taking struts out, because the only thing thing really holding broken strut mounts is the weight of the car. 

yes the mounts wear out just like anything else

Thanks