Recognizing Stress and Fear in Cats

I've been thinking a lot about this lately because Kettle has had ear mites and Teal is just... a lot. I work as a vet tech so I see the clinical side, but at home it's different. How do you guys tell the difference between a cat that is just being grumpy or picky and a cat that is actually stressed or scared? I want to make sure I'm not overreacting to Teal's vocalizing or missing something with Kettle.

I worry about this with Mochi. She is only a year old and still figuring things out. I think the biggest thing for me is watching her eating. If she skips a meal or hides in the same spot for hours, I know something is up. It reminds me of when I was caring for Patty, my 12 year old. She is heartworm negative but old, so any change in her routine is a big deal. I found this thread about subtle signs very helpful: Subtle signs my cat is stressed. It lists things like dilated pupils and flattened ears that I didn't always notice.

Oh my gosh, this is so timely. My baby arrives next month and I am terrified Chloe will regress. She is already a bit shy, which makes me nervous. I read this thread Helping my cat adjust to the new baby and it said to keep the bedroom door closed, but I don't know how to tell if she is stressed by the preparation vs just being herself. Does anyone have specific signs to look for when a cat is feeling overwhelmed by changes in the house? I feel like I am missing the early warnings.

For me, it is about the personality shift. Pearl is 11 and has hearing loss, so she relies on visual cues. If she starts swatting at things she normally ignores, I know she is anxious. Peanut is 4 and a bit heavy, so he isn't very mobile, but if he stops coming out to sit with me, that is a red flag. I think it is important to establish what is normal for your specific cat. I wrote about this a bit in Tips for a shy cat meeting guests, but it applies to general stress too. If you are worried about health issues causing the behavior, check out Monitoring my senior cat's heart health for how to distinguish medical from behavioral.

Thanks everyone. I just posted an update in a follow-up thread Kitten health checklist for first year where I went over the specific symptoms we are seeing with Kettle and Teal. It turns out some of what I thought was stress was actually just the ear mites making him uncomfortable, but Teal's vocalizing is definitely linked to her routine changes. I am going to try the quiet room suggestion from jessc86.