My 10 year old cat has started to pull out tuffs of his hair. Can you explain why?
There are a few different possibilities. Cats will do this because they are itchy from an allergy of some sort. The most common allergy in cats is to fleas.
Cats can also pull their hair out due to a nervous disorder, although that is not as common.
If a cat has any small mats in their fur, they will try to pull those out.
Your cat is also at the age when certain "older cat" disorders can set in. Hyperthyroidism is one of the most common and can result in hair loss, poor haircoat, mats, and many other symptoms. Diabetic cats also lose hair.
It's very difficult to know which of these conditions, if any, are most applicable to your kitty without an exam and possibly bloodwork. That is what I would have to recommend.
Good luck. Thank you for writing,