He's going through a bad/difficult/rough 'patch' [='spell'] right now.
The chair's original paint is still visible 'in patches'. [=in spots]
The doctor 'patched' him 'up', so he's going to be as good as new.
(..) do you ever get any free time? Oh, yeah. Lots. - Bye. - OK. - What are you doing? - Nicotine patch. Helps me think. Impossible to sustain a smoking habit in London these days. Bad news for brain work. - It's good news for breathing. - Oh, breathing! Breathing's boring. Is that...three patches? It's a three-patch problem. Well...? You asked me to come, I'm assuming it's important. Oh, yeah, of course. Can I borrow your phone? (..)2010 TvShow: Sherlock Title: A Study in Pink Season: 1 Episode 1