My brother experienced mild hair loss this year, but thankfully he was able to take action and now it is resolved. His suspicion is that he got too stressed causing that to happen. It's really important to build a healthy lifestyle especially when our age increases. We can't certainly avoid any disease or health problems as they're part of nature but at least we can lessen.
I wish you a successful operation and fast hair recovery!
I found out too late that getting some sort of topical solution once you start to notice hair loss can actually help a lot. At least where I live this product isn't even that expensive so I'm kicking myself for not starting to use it when I began to notice hair loss a few years ago.
Topical solution can treat the symptoms but not the root cause, I think you should dig deeper what's causing you hair loss in the first place.