There are a few different contexts where the adage "laughter is the best medicine" might be used, some of which are quite literal, while others are a bit more figurative. The basic idea behind the saying is the belief that mood can have a strong effect on the body’s ability to repair itself. The term is also often used to reference laughter’s ability to heal emotional problems or help people overcome relationship difficulties. There is actually some scientific evidence to support the idea that laughter can be helpful in both a physical and emotional sense, so while it may not be entirely true that laughter is the best medicine, it could have significant benefits.
In some cases, people may use the term "laughter is the best medicine" in the context of physical healing. There is a general belief that someone’s mood can have a direct relationship with the person’s ability to fend off an illness or overcome an injury. If someone is suffering from some kind of serious medical condition and also dealing with a dark depression, there might be a concern that the individual’s mood could hamper his ability to recover. Doctor’s and family members may even go out of their way in an effort to cheer the person up, sometimes through the use of comedy.
Another common use of the term is in relation to dealing with bad moods or emotional problems. For example, if someone is dealing with an emotional trauma, there might be an effort to use comedy as a way of getting the person’s mind off his troubles. Laughter is known to be associated with the release of certain brain chemicals related to feelings of euphoria, so there is some evidence to support the idea that laughter helps in fighting off depression.
Some people believe that laughter is the best medicine to help in mending troubled relationships and experts suggest that laughing helps people form bonds with each other. The intentional use of humor to generate laughter is usually a big part of courtship, and once people enter a long-term relationship, laughter still may be crucial in keeping them together. If two people are having romantic difficulties, one of them might try using laughter to help soften the other person’s mood and speed up forgiveness. This use of humor to help reaffirm bonds and recover from arguments is also common in platonic friendships.