Laughter is one of the most enjoyable human conditions, but even it is not without its dangers. There are cases when people died of laughter. But even if it doesn't come to such dramatic consequences, laughter can cause some trouble, for example, cause stomach pain.
Laughter is not unique to humans. Some monkeys laugh, in particular gorillas and chimpanzees. Their laughter manifests itself as a reaction to tickling. There is such a reaction in people, but human laughter often acts as a manifestation of a sense of humor - one of the highest feelings formed in the course of evolution, not so much biological as social.
Physiological mechanisms of laughter
There is no consensus among scientists about the evolutionary origin of laughter, but one thing is clear: laughter has a certain effect on hormones. Scientists from Loma Linda University (USA, California) have found that laughing increases the level of hormones that stimulate the immune system, substances that affect the synthesis of adrenaline. The number of endorphins, which are figuratively called "hormones of happiness", also increases. In fact, these substances are chemically similar to pain relievers. All this suggests that the original purpose of laughter is to help cope with stress, to protect the body from situations that somehow traumatize it.
The most serious traumatic situation that an organism can face is … death, the complete cessation of its existence. But even on the eve of death, the body tries to protect itself from suffering by throwing endorphins into the bloodstream. That is why people who have experienced clinical death talk about fantastic visions.
The "trigger signal" for the release of endorphins into the blood is a decrease in the amount of oxygen. In real death, it is associated with cardiac arrest and cessation of breathing. With laughter, this is ensured by a change in the nature of breathing, which becomes spasmodic.
The danger of laughter
Spasmodic breathing during laughter consists of a forced inhalation and a subsequent series of short exhalations, occurring with great effort. This expels more air from the lungs than usual.
A series of short, enhanced expirations under high pressure is provided by the respiratory muscles, primarily the abdominal muscles and the diaphragm, the muscular septum that separates the chest organs from the abdominal cavity. By providing short, frequent expirations, these muscles are forced to work at a higher intensity than usual. Like all muscles, they can hurt when overworked, so a prolonged fit of laughing can lead to abdominal pain.
Abdominal pain is not the worst thing that can happen. Breathing problems when laughing can even lead to death. This happened with the ancient Greek philosopher Chrysippus, the Italian Renaissance writer P. Aretino, the Scottish aristocrat T. Urquhart. In the latter, a fit of deadly laughter was caused by the news of the accession to the throne of King Charles II Stuart.
Laughter is certainly beneficial for both health and psychological well-being. But in everything - and in laughter as well - one must observe the measure.