Hedge thinning

[AusRay]

Hi everyone,
I'm very new to gardening and I purchased a house with a beautiful garden however my hedge has started to thin and now has holes in it. I don't even know what type of hedge it is. The inside is hollow and alot of dead branches or empty branches. Do I have to remove these for them to grow back?
Any help would be appreciated.

 

[Tetters]

Mystery SOLVED – Privet Hedge Dying for No Apparent Reason

You have a beautiful hedge that has lasted for almost half a decade now. However, you are noticing that certain parts of the privet row have started to wilt for no apparent reason. The leaves of the privet hedge are turning yellow at first, then purple or even black. The decay has started from...

blog.fantasticservices.com

I have provided the link here as it will give more information than I have time for at the moment. My very first thought was ''oh no - honey fungus !