Does anyone know the medical reason for / or ever had dark colored finger nails? (the whole nail bed)?

This weekend I noticed a male relatives' fingernails, and since I don't have on nail tips anymore, mine are clear and healthy, which made me notice how dark and unhealthy his looked. I asked my sister who is a nurse and she said it depends on alot. I'm concerned but I had a hard time describing it to her.


She said it could be several reasons, loss of oxygen, diabetes, etc. I searched online for diagnosis or to find a picture online of his nail so I could better describe it. So I thought that if I presented this question to you guys someone would give me some insight.


As many of you know men are not as receptive to going to the doctor unless they think it's really warranted, (other than dark fingernails), but I know it's a symptom of something else going on in his body.Does anyone know the medical reason for / or ever had dark colored finger nails? (the whole nail bed)?
I agree with your sister, that seems to be a great indicator or low oxygenation in the blood, cause can be from many things.. congested heart failure, chronic obstructive pulmonary disorder, yes even diabetes. there is a way to check capillary refills, press on his nail bed to see if they true white, then release if it takes longer than 3 seconds to go back to the color that they were, there is an oxygenation problem,


he should get it check out by a doctor. I know men are stubborn.. I am married to one, and I am a nurse and he still doesn't listen..


Good luck