A birdfeeder outsides a sick person’s window has a magical healing effect. Of course it can’t replace following the advice of a physician, like taking aspirin, or whatever’s prescribed, but helps quite a bit. This helps even if the illness is just feeling depressed, tired, a cold or something else relatively minor.
It has been proven over and over that people who experience nature are able to recover more quickly and completely from stressful events. A birdfeeder is one of the cheapest and quickest ways to experience some nature. Both heart rate and muscle tension decrease much faster in stressed individuals when watching bird activity.