A fair amount of research has been done which shows that laughter is very healing for individuals with serious health problems.  I have found that to be true in my own practice.  Even silly jokes can ultimately get someone to loosen up and over time, relax, which aids healing and just generally improves how a person feels.  You can put things in perspective with humor.

In Jin Shin Jyutsu®, there is a specific flow (a sequence of placing hands on energetic focus areas) that often makes people laugh.  It is useful for any problems with legs or feet, as well as vascular conditions.  If you think about it, this seems to indicate that laughing "gives you legs", and obviously it helps your heart.   Laughing gets you back into the flow of life.

While a discussion of herbs that may make you laugh is perhaps beyond the purview of this particular article, there are herbs that help relax the nerves and contribute to a relaxed alertness as well.  They help you "get the joke". These are often referred to as tonic herbs, or adaptogens.  Ginseng is one example, rhodiola another.   Peppermint is also good for this purpose, as is rosemary.  Both these herbs help your circulation which in turn helps the flow of air through the body, which helps focus and clarity.  Nervines, which focus on relaxation, are plants such as valerian and passion flower.  Flower essences such as dill and nasturtium can also aid in calm focus, clarity, and an openness to being amused by what one sees instead of rushing by it.  Definitely worth a look!