Love the title of your post OP. LOL.

I cut those clumps out carefully -- the ones I can't brush out. That's really the only way to deal with it. If he has a lot of them, take him to a groomer to get them shaved off and his hair will regrow (and as it does, brush regularly to keep it mat free). They aren't comfortable for him either.

My buttons, my buttons, my four groovy buttons...!

It's harder to get back there the older they get. Get a grooming spray and spray the brush, then work on the fur.

So...My nine yr old kitty is getting a bit overweight and I have noticed over the past three months or so, has developed huge fur clumps on his back. I have tried to brush them out, but he always meows like he is in pain so I stop. Yes, yes...I know, I am such a sucker. LOL.

Anyway, his back fur looks just awful and I am getting worried.

Any suggestions?
Thanks in advance.

Also, what causes them? He has never had them this bad. He had them last summer, but just like two or three.