Every so often, in one of my wu-su martial arts classes someone always inquires about the so-called Din Mak "death touch." This usually comes about when we start teaching the concept of Chin Na Fa. "Chin" in Chinese means to "to seize of catch," and "Na" means to hold and control. It's a style that uses joint lock manipulation, chokes, throws, and pressure point attacks. It's the pressure points that get people to inquire as to Dim Mak. Simply put, in Chin Na, pressing techniques are used on nerve endings to cause extreme pain and/or unconsciousness. This is a far cry from the Din Mak "delayed death touch," which everyone wants to learn.
Chin Na does make use of "Duann Mie" (another word for Dim Mak which involves sealing or blocking the vein/artery by pressing). This can also involve cavity pressing or meridian pressing, which exemplifies Dim Mak. According to ancient Chinese medicine, the body's life force (Chi, Qi or Ki) travels though invisible channels called meridians. Any disruption in the flow of this Chi force can cause illness or disease. The meridian flow concept is prevalent in the use and theory of acupuncture whereby needles are inserted into different points on the meridians in order to counteract an illness. Din Mak evolves along the same theory: attack the points and you disrupt the flow of energy, thereby causing injury or death.
There is no question that attacking a nerve ending or pressure point can do great harm. A thumb press on the left common carotid artery (just below the ear) can block blood flow to the brain and result in unconsciousness or worse. And there are numerous pressure points that we study on the body that can have similar affect. Also, a blow to a vital part of the body can also result in injury. Note that one of the most common cause of sudden cardiac arrest in young athletes is a condition called Commotio Cordis, where a non-penetrating blow to the chest occurring within a specific portion of the cardiac cycle can cause severe trauma. But this is a far cry from the "death touch."
What is controversial about the Dim Mak concept is this idea that that you can attack someone simply by touching a vulnerable area and producing a delayed reaction whereby the subject incurs death hours or days later. Medically speaking, there are instances of a delayed reaction due to an injury. You get into a situation where you sustain an injury and you don't treat it, after a while it's going to get worse. You sustain a strike to the kidneys and you start peeing blood, and you don't see a medical person right away, you have problems. But a delayed injury by mere touch, without the subject even feeling or knowing until the time of death? This leads to much debate and controversy, and skepticism on the part of many.
This controversy was fueled in part by a 1985 article in Black Belt magazine which attested that the death of fabled Kung-Fu icon Bruce Lee in 1973 was due to a "delayed reaction to a Dim-Mak strike he received several weeks prior to his collapse." Following in this vein, others attested that Bruce Lee may have been the victim of the "Quivering Palm technique" which also incurred a delayed reaction. I remember an episode from the 1970s TV series Quincy, starring Jack Klugman, whereby a martial arts movie star dies mysteriously while making a movie. And guess what? Dr. Quincy discovers that it was due to a Dim Mak strike 10 days earlier.
Let's put it in perspective. This "delayed death touch" business has become fodder for TV and action movies. In the 1990s karate instructor George Dillman invented a style called Kyushojutsu that he claimed had qi-based attacks without physical contact, the "no-touch knockout" techniques." Upon third-party investigation the whole thing was denounced as fraudulent. Another parctiioner, Erle Montaigue, published a number of books and videos on Dim Mak. He claimed that he had learned the technique from a master named Chian Yiu-chun. Problem was, as Montaigue later stated, this master was an illegal immigrant, making his existence very difficult to verify.
Now, I'm not saying that this delayed death touch may or may not exist. If you believe in your mind it exists, then it does. If you don't believe so, then it doesn't. Just as if you believe Voodoo exists, it does. If you don't believe so, it doesn't. Just be aware that if you come across an instructor who states he can teach you the "delayed death touch" or the "five point palm exploding heart technique" (as shown in the Kill Bill Vol. 2 movie) and assures you it can be done if you pay up ex-amount of dollars, head for the door. That person may be a charlatan, and is taking you for a ride.