(The following is a first article from a new contributor, Dr. David Zhang. David is an American Chiropractic and Chinese medicine doctor at my clinic, the International Medical Center in Beijing)

Christmas is over – the children have returned to school. Vacations are taken,  travel is done.  Moms breathe easier and Dads return to work and life returns to normal.  It’s a calmer time before next holiday rush.

But why can’t I relax to enjoy this quiet space?  My neck and back feel tight and stiff, and my joints and bones are hurting.  And people in my office and the kids in school get sick with sinus infections or coughs or sore throats.  Is it because of the cold weather?

In animals and human beings, the barometric pressure in the joints is higher than the outside air’s atmospheric pressure.  These two pressures balance against each other to equalize, which helps to keep joints the stable and holds them in better alignment.

When you were young, you may have “glued” a wet snack wrapper to a smooth glass window surface.  It was atmospheric pressure causing the paper to hold to the glass.  Similarly, when the weather turns cold and the atmospheric pressure drops, the barometric pressure inside body joints increases to balance, sometimes causing an individual to feel more swelling in the joints while at the same time as the stability of the joint is slightly decreased, making it easier to lose the alignment.  For some of us, the increase in pressure coupled with a slight misalignment might translate in a feeling of tightness or stiffness, or even in achy bones or joints for some.

Also, cold weather constricts tissue and blood vessels, which can decrease the blood flow to tendons, muscles, and ligaments. And this is why it’s important to take extra time to warm up the body before any physical exertion during colder weather.  The body is more easily injured in the winter than in the summer.

As cold air is breathed in through the nose and mouth and passes down into the lungs, the cold air cools down the membranes lining the surface of the entire air passageway.  Blood vessels begin to shrink which decreases blood flow, so there is a somewhat lower volume of white blood cells and other immune cells flowing to guard your respiratory system.  Plus, the decrease in atmospheric pressure will change the sinus and ear pressure comparatively.  Consequently, and the upper respiratory system is somewhat weakened and more vulnerable to attack from virus and bacteria.

Now  is a good time to tune up the body again to handle the stress of winter, and focus  on health maintenance .