Every fall and winter, clinics fill up with people who feel suddenly miserable, or who have a lingering cough that will not quit. Three viruses often drive that wave: influenza, COVID 19, and respiratory syncytial virus, better known as RSV. All three infect the nose, throat, and lungs, and they spread through close contact and respiratory droplets. Because they target the same body systems, they can produce overlapping symptoms like cough, fever, congestion, and fatigue. That overlap is why...
