Here is my opinion as a recruiter (of course recruiting is highly subjective and everyone has their own biases in hiring)
1. If its your first job after a gap, don't say its a health reason. They will probably not ask more but they'll probably mentally downgrade you because 'Are they really okay to come back to work?' If it's further back, it'll be less of an issue. This goes triple for any job that is physical.
2. Depending on hiring person, I find 'I was caring for a family member full time' to be a good reason for a gap that I won't question.
3. If you have the opportunity while in a gap, get a certification or degree. Then you can use that as a reason for your gap and it could potentially turn the view of that gap from negative to positive.
4. If you have a "good" reason, most people understand. I speak to people daily who were a Covid layoff and we don't count this gap against them. I also sometimes talk to people who have to explain gaps around 2008 with "Well that was during the financial crisis" and I go say no more I understand.
4. If you don't have a "good" reason, pretend you do. Don't lie but make it sound like the gap was a thing you chose. "I had the opportunity after leaving my last job to take a few months before looking for work again." "I was able to work on building my home business (Ebay, etsy, etc), but now I'm looking for something more stable."