As blood flows into and out of the heart’s chambers, it passes through tiny biological doorways that ensure everything flows in the proper direction at appropriate intervals. These doorways are heart valves—tissue flaps that open to let blood in and then close to prevent it from flowing backwards. The system works great unless the valve becomes too narrow or doesn’t seal properly.
Travel increases during the holidays, coinciding with cold and flu season. Being cooped up in a plane with strangers coughing and sneezing their way through the flight, along with the added stress of travel and its potentially dampening effect on the immune system, can leave you vulnerable to illness.