 Hundreds of millions of operations are performed every year, and the risk of death is typically around a half a percent, to which patients might say things like, I could just die as easily crossing the road, making it clear they really don't understand the difference in magnitude of risk. One way to communicate risk is by analogy. For example, just going under anesthetic carries about a 1 in 100,000 chance you won't wake up. How much is that? Well, that's about the same risk as an expert skydive. Okay, but that still may be kind of hard to wrap your head around. It's hard to think in terms of small numbers. Like imagine discussing a 17-10-thousandths of a mile by 22.7-thousandths of a mile rug. Like how big even is that? We need more digestible units. Enter the micromort as a unit of comparing and communicating risk to patients. A micromort is a unit equivalent to 1 in a million chance of dying. 1 in a million is like the chances of flipping a coin and getting 20 heads or tails in a row, or a little less than the chances of getting a royal flush. But the real utility is to help compare different risks to one another using the same metric. For example, driving 100 miles entails about a 1 in a million chance of death. So that's 1 micromort. Scuba diving is like 5 micromorts per dive. So each dive is as risky as driving 500 miles. So now we have a way to directly compare the risk of surgical procedures and common activities. So like giving birth is as risky as driving from New York to LA and then back again. But getting a caesarean is more than twice as risky. Even something like a simple hernia repair carries the same risk of dying as like skydiving 200 times. Now obviously sometimes you have no choice, but death from varicose vein surgery or circumcision could probably be avoided. I was surprised to learn that regular horseback riding is like four times deadlier than rock climbing. But like getting chemo and radiation for head and neck cancer is riskier than rock climbing for 500 years, driving 5 million miles or jumping 5,000 skydives, etc. One leading cause of death I really didn't talk about and how not to die is accidental death. We have approximately a 1 in a million chance of dying just by accident every day of our lives. And about half of that risk is dying in a car crash, based on U.S. averages. Then there's all sorts of other ways I'm surprised to learn. Americans have about a 1 in 200,000 chance every year of dying from a foreign body entering an orifice other than the mouth. Other things we may want to avoid include climbing Mount Everest, about 30 times riskier than coal mining or base jumping. Trains and planes are actually equivalent over the same distance, but riding a motorcycle is about 50 times deadlier than riding in a car. Though cycling to a destination is riskier too, about 10 times as deadly as driving in the near term. Here's a good example of how one can use micromort comparisons to help put things in perspective. Certain types of breast implants can cause a rare type of cancer, a type of breast implant associated lymphoma. You can imagine how scary this is for the millions of women who have implants, but check out the risk compared to the risk of other common activities. Your risk of dying from this kind of cancer is less than a single day of skiing. Now it's probably better to die quick on the slopes and all the slow suffering of cancer with the risk of bankrupting your family, but at least it can put the risk of the implant cancer killing you in context.