Lo que provoca el clima...

I want to talk about the weather, and not to make small talk. I want to talk about how the weather affects our bodies and our lives. Our instinctual ancestral memories remind us of the power of nature. We watch major hurricanes, tsunamis, volcanoes, blizzards and tornadoes change entire countries. These massive cataclysmic weather events are awesome indeed, but the weather actually affects your biology 24/7, as it constantly applies stressors or supports every breath you take. In fact, you could say your body is its own perfect weathervane -- your mood, headaches, and heart health are much more subject to changes in the weather than you might think. Just like a house built to withstand the elements, you must take care of yourself or the weather will expose you.

I teamed up with Al Roker for my show on Friday to talk about the fascinating and important intersection of physiology and meteorology. Your body is mostly fluid and gas pockets, along with some hard bones to keep you standing up. All of these elements that make you "you" are interdependent with nature's elements. You probably remember your grandmother saying her knee was acting up, so it must be going to rain or perhaps you've gone out one cold morning and felt an intense sinus headache. These were responses to changing pressure systems that ebb and flow as fronts come and go. Lower pressure, or a "falling barometer" as Al would say, is going to cause some sinus pain in those who are inflamed, infected or live with chronic sinus pain.

Pressure affects joint pain in a fascinating way. Did you know that at all times every square centimeter of the human body has about 14.6 pounds of pressure on it? This constant pushing keeps us together. It increases when you go underwater, and lightens a bit when you ascend in airplanes. But this pressure is always with us, and the slightest deviation can be felt in the suction cups called our knees, hips and shoulders. If pressure lessens, our joints start slipping and it's time for some ice, an ace bandage or aspirin. You can literally feel a storm brewing.

We heart surgeons have long known that there are many more heart attacks in the winter -- in fact, a whopping 50% more. When you go outside in the freezing cold, your blood gets thicker and your blood pressure rises, which creates the perfect storm for a heart attack. Plunging suddenly into freezing cold water can cause this to happen, but just being outside when it's cold can increase your risk if you are unprotected. Cold air also causes tiny cracks in lining of the bronchial tubing in your lungs which then swell and produce fluid. The expression "come inside and put a coat on before you catch a cold!" was referring to this process -- there weren't more cold viruses out in the snow that your grandmother was referring to, your poor lungs were just having a heck of a time with cold dry air. Flu viruses thrive in cold temperatures also, and we have an entire season named for the flu as a result. Wednesday's show on medical myths highlights several more "cold weather" related fallacies.

Perhaps the most recognizable and far-reaching weather related impact is the receding daylight hours in the winter months. This is a particularly good time to talk about this because the winter solstice, December 21, is the day with the least amount of sunlight each year. I bet most people reading this have at least some reaction to the lesser daylight in winter -- the most common effects can range from simple sleepiness in the afternoon as the sun goes down early to outright depression. It's fascinating why this happens and there are several things you can do about it. A gland in our brain called the pineal gland is our internal sensor of light. Whether our eyes are open or shut, this gland senses sunlight. Once the sunlight is gone for the day, your pineal gland produces a hormone called melatonin. This causes you to become sleepy and as you produce more melatonin, you produce less serotonin, which is associated with depression. It can be subtle and manifest as a general crabbiness or gloomy mood, or it can be very severe and require medical intervention. Have a conversation with your doctor about how you are feeling in the winter months, or try to get somewhere sunny for a few days. A high power light maker is another great option -- just make sure you buy the kind that doesn't produce harmful UVB rays. Your overworked pineal gland will thank you.

So colder temperatures, changing barometric pressure and less available sunlight are three things that are starting to affect us as winter roars into full swing. By being aware of these things, you can be more comfortable, safer, and your biological forecast will be better than the meteorological one. But more importantly, stop for a moment and reflect on the unbelievable interdependence we have with everything that is going on around us. While a five-day forecast can tell us what our sinuses, joints, hearts and moods are up against, just as we would take precautions and protect ourselves by packing an umbrella or wearing a warm coat, we can do the same for our bodies. So tune in Friday and watch Al Roker and I show you how to make sure the almanac isn't your personal prophecy.