It may well be hormonal but this is what you need to find out.
I am trying to reassure you but it's not clear from your first post, what's going on. The rule is any bleeding- even one drop- after 12 months with no bleeding at all, must be investigated.
If you had no bleeding for a year and then you started spotting and have now got a heavy bleed, that's why it needs looking into.
If you have not gone a whole year with no bleeding at all, you could still be peri meno and this could be a heavy bleed due to lining building up, but at 58 that would be quite rare.
I don't know if you have heard of endometrial hyperplasia? This is where the lining gets thicker and thicker because it's not being shed (as in a period.) It is a hormonal condition due to excess estrogen. Eventually the lining comes away with a heavy bleed. But the risk is that as it gets thicker, changes can occur that could mean some cells become cancerous. Hyperplasia doesn't automatically mean cancer, it's just that it can develop from it.
If you have a scan they will look at the lining , it's thickness and any abnormalities. They may also take a biopsy as a separate procedure. (I've had all of these which I why I'm sharing.)
Let us know how you get on? Good luck.