Your body continually goes through changes based on different activities you do. Some activities or actions your body goes through are not healthy, but others are.  Laughter is one thing that is healthy for you.

Laugh Away those Calories
When you laugh your body goes through specific changes. These changes are very similar to the changes your body goes through during exercise. In fact, laughing one hundred times a day is the same as spending fifteen minutes on a treadmill, or an exercise bike. When you laugh your heart rate, blood pressure, and blood circulation is increased.  Your breath rate also increases, you take in more oxygen, and release more carbon dioxide.
Laughter also activates certain muscles, toning them and easing any tension. The muscle groups that are activated most often are the diaphragm, abdominal, intercoastal, respiratory accessory, facial, and occasionally muscles in the arms, legs and back. Just like after exercise your body returns to normal. After laughter your body also returns to normal. This is called the resolution phase. After a good laugh you feel very refreshed, so you should definitely make a point to laugh as much as you can everyday.

Laughter the Best Medicine
Besides keeping you in shape laughter also has some curative properties.  There is actually a whole field of science dedicated to the study of the connection between emotions and the immune and nervous systems; it is called psychoneuroimmuunology.  A study was conducted by Arthur Stone of S.U.N.Y revealing that the Salivary Immunoglobulin A response was higher on days when people were in a good mood than when they were in a bad mood. Salivary Immunoglobulin A is the body’s first defense against infectious diseases that enter our body. This was proven again by Kathleen Dillon of Western New England College.  Her research showed an increase of the Immunoglobulin A in her subjects after they viewed a humorous video.
Other research done by Dr. Lee Berk’s team at Loma Linda University showed that the number and activity level of natural killer cells that attack viral infected cells, and some types of cancer and tumor cells.
Another study conducted by Berk showed that laughter increases a chemical called gamma interferon. Gamma interferon acts as an activator for the immune system, in other words it tells various components of the immune system to “turn on.” These studies prove that the immune response of the body is related to the mind and emotions.  Positive emotions strengthen the immune response while negative emotions suppress it.

Humor and the Brain
Laughter causes a noted change in the brain, making it an effective form of therapy.  When you laugh the brain’s chemical transmitters (neurotransmitters) and the catecholamine hormones increase, strengthening your ability to stay alert.  Laughing can also be a replacement for painkillers. Your brain releases more endorphins, which are natural painkillers, when you laugh.
Studies show that laughter can reduce stress. This occurs because laughter decreases the serum cortisol levels. Serum cortisol is actually elevated during a stress response, so reducing these chemicals can actually ease tension and stress.