Its worth noting upfront that this video is a hard one to get through; more time will likely be spent staring at ones nails than paying attention to the important facts on display. Then again, theres always the replay button.
Whatever the case, anyone who wants to see nails as more than just parts to paint or break is in luck. It starts with an exploration of the nail matrix, a layer underneath the nail that helps decide what color it has. But its also capable of revealing what sort of health problems, if any, a person might have; as exciting as it might be to have blue nails, the blood flow problems they might signal arent quite as ideal.
Its an informative video, but its sagest advice may come at the end: dont get medical advice from the internet. Seeking out a doctor is always a good choice.