Cat pulling her hair out

My cat, female 15 years old, pulls her hair out in tufts, leaving it on the floor or in her mouth regularly. It is a strange behavior she only developed in the last year. During this time, she has been diagnosed with hyper thyroid and had an infection that caused 12 teeth to be pulled out (due to the throw up acid from the infection and hyper thyroid). She is off her meds now and in better health, eating, drinking a lot of water and urinating and defecating regularly.
   
Should I brush her more or is this a behavior indicating something serious?
   
Thank you

Yes brush her everyday and you should have her thyroid rechecked. Drinking alot and pulling hair out might be from the dose of the meds not being correct. Her levels might of changed or they never had the dose right in the first place. Good luck! When they do the blood pannel they should be checking for liver/kidney problems and diabetes also.