Top Level Menu Items Not Clickable

When I have menu items in my primary menu that have sub-menu items underneath them, the primary item then is no longer an active link. I have product categories and would like to use those top level menu items to describe the whole category, and then have specific items within the category beneath them as sub-items in the menu. But currently I don’t have a way to allow my users to click on those main items to get category information. Possible to modify?