So my cat, 15 yr old female, has hyperthyroidism and has had issues lately with passing hairballs. We got a new cat last year and he sheds a lot so not sure its that or something going on with her stomach. But last night was the worst episode. She was again struggling to get a hairball out and it was half hanging out of her mouth. She was running around panicking and I went and pulled the hairball out for her. When I pulled it out, there was blood on it. And seconds later, she laid down on her side, her eyes went blank and her mouth was wide open. Me and my SO are freaked out at this point but luckily she gets up. We immediately load her in her carrier and take her to the hospital. While we were waiting she seems to settle and the doctor ended up giving her antacids, cerenia and x rays and they don't find anything. Today, she seems more like her normal self. But I'm still freaked out. Why did she lie on her side with her mouth open? And why was there blood? The hospital vet said the blood could be from the hairball getting caught. It's just with how she looked...she looked like she was passing and what people say what happens to cats when they pass. I'm soooo worried.