Blue fingernails and toenails: what could it be?

A few days ago, I noticed something strange—my fingernails on both hands have turned this bluish tint from the base down to about halfway. It’s actually hard to pin down the exact shade; sometimes it looks gray, other times more purple... At first, I thought my eyes were playing tricks on me, but anyone else looking at them can see it too. The weirdest part is how quickly it happened, practically overnight, and I can't find any obvious reason for it. I know discoloration like this can be a red flag for heart or lung issues, which is why I'm getting anxious, even though I just had a full checkup with my cardiologist and everything came back perfectly fine... It might be worth mentioning that this blue crescent shape is most noticeable on my pinky and ring fingers, while my thumbs look completely normal. I'm starting to get a little scared, so I was wondering if anyone here has dealt with something similar, or if there's anything else this could point to besides some kind of lung infection?
I'm not sure if it could be linked to anemia since I've struggled with that in the past, but my latest blood work from about a month ago showed nothing out of the ordinary.
I am currently taking Vitamin D and an anti-anxiety med, though I really doubt it has anything to do with my prescriptions...

You might just have some poor circulation in your hands

Go see a doctor and show them those bluish tints on your nails.
That could be a sign of low blood oxygen levels, and there are plenty of different reasons why that happens.
Emphysema is common, but it could be anything—or nothing at all.

Bottom line: get to a doctor and tell them about the discoloration.

I’ve recently noticed that my left foot occasionally turns completely blue... it’s never happened before, and I’ve been spotting this over the last month or two.
I gave birth about four months ago, and ever since the delivery, I’ve felt this numbness stretching almost the entire length of my left leg. Honestly, I didn't think much of it at first—I just chalked it up to the physical toll of childbirth and expected it to eventually fade away...
That sensation has actually diminished somewhat, but then I noticed these blue nails... and the strange thing is, it only happens while I'm sitting down.🤷

Should I be worried? I am aware that cyanosis—blue-tinted nails—is typically an indicator of poor heart or lung function, but in my case, it isn't constant; it only occurs sporadically while seated, and strictly on my left foot.

I mean, honestly, I think you should probably go see a doctor just to get everything checked out, you know? Just to be safe and make sure nothing is actually going on.