The pulse, in Traditional/Classical Chinese Medicine is one of the windows to our body's inner workings. To be able to proficiently feel and interpret the properties of the pulse (the radial artery pulse) is to have great insight to someone's health and condition.
You see it in Chinese WuXia flicks all the time where the doctor puts three fingers on someone's wrist and tells them exactly what's wrong with them in the matter of seconds. Or an even better one is reading a woman's pulse, immediately exclaiming, "Congratulations, you're pregnant!" and drama erupts from there. They're referring to the 喜脈, "The Pregnancy Pulse".
It's bullshit. Well, no. It's not totally bull. Let me qualify that.
Firstly, you need to read both sides, the left and the right. Not just one.
Secondly, it takes more than a quick touch to get a proper reading. There are certain patterns that can occur every 25 or more beats (rest pulse), so you need a reading of more than 50 to really read someone properly. Most doctors will take about 60 seconds on each side which is approximately 60-80 beats under normal circumstances.
Thirdly, there IS a certain feel to the pulse when a woman is pregnant, it's called 滑脈, a "slipping" pulse (that's referring the way in which the pulse is beating, it's not saying that her pulse is stopping). But a woman's pulse can be that way during the last few days of her Luteal Phase (a few days before her period is due to start). I'm thinking it has something to do with the progesterone levels and thus, the state of the pituitary gland, but I can't be sure because I don't think that's the only thing in the body that's going bananas at about that time.
If she's missing her period AND she's feeling nauseous in the mornings OR other combinations of symptoms then all of that combined with the 滑脈 will almost certainly confirm pregnancy. I have no idea what the pulse is like in chemical pregnancies or false pregnancies.
Fourthly, I think men can have a "slipping" pulse as well, though I'm not sure about that.
And lastly, I also think that other conditions/illnesses can cause a "slipping" pulse.
Hmm... I have a few good questions I can ask next time. =)
Pulse reading is absolutely not the be-all and end-all of diagnosis. Most doctors will only use the pulse as one dimension in their analysis. The pulse is not an infallible source and, on infrequent occasions, can show conflicting signs. There are really good doctors who seem to be very in tune with this one method and can diagnose almost anything from pulse readings alone. But they are very rare.