Clump of hair on back

Hi everyone,
I hope you can help! My four year old cat, Mishka, has this big, hard clump of hair on her back. It almost looks like a dreadlock.
Well, I cut it off today, and the part that was closest to her skin was all bundled and had dandriff like flakes in it. It even kind of looked like laundry lint...any suggestions? Is this just lack of brushing, or could she have an infection?
Thanks for any input!!!!
Nicole

Lack of brushing. It's normal to find it under mats- it's just months of accumulated dander that had no place to go.

Thank you!! I will start brushing more often. What a relief!

Is the cat overweight?
I groom cats, and often the clumpy hair on their back happens when they can't twist around far enough to groom themselves- it's fairly common.

If not, just brush it once in a while and double check with a good metal comb, and he'll be fine.