A kiss is to touch with the lips or press the lips against something or somebody. It is used as an expression of affection, respect, greeting, farewell, good luck, romantic affection or sexual desire.
Kissing requires significant muscular coordination; a total of thirty-four facial muscles and 112 postural muscles are used during a kiss. The most important muscle involved is the orbicularis oris muscle, which is used to pucker the lips and informally known as the kissing muscle. Lips have many nerve endings so they are sensitive to touch and bite.
"Kissing disease" or Mononeucleosis, known as Mono for short, is caused by the spread of a "bug" or virus called Mono.
Infectious mononucleosis. (also called Mono) is spread through kissing, colloquially referred to as "the kissing disease" and is caused by an infection with the Epstein-Barr Virus (EBV). After exposure to EBV, there are usually no symptoms at all, in fact, up to 95 percent of adults have antibody evidence of past EBV infection even though the vast majority recalled no related illness. For reasons that remain unknown, only some people develop Mono after exposure to EBV. With symptoms such as fatigue, headache, muscle or joint aches, fever, enlarged lymph nodes, and sore throat. While it is true that the virus is shed in the saliva and can be transmitted by kissing, Mono is not a highly contagious illness and it can also be transmitted by other means, such as coughing or sneezing. Preventing the spread of EBV is not easy since there are often no symptoms. Even when there are, one may be contagious before the illness is recognized.
By NOT kissing that special someone, you're also NOT exposing yourself to the 500 or so bacteria in your partner's mouth, and you're NOT letting viruses in either.
Kissing (the exchange of saliva) is a great way to pass a virus, which is specially equipped with sticky proteins that allow it to attach to a person's healthy cells, the virus hangs on to the cell's surface until it can get in and co-opt the cell's machinery for its own purposes.
The virus incubates over a few days and the infected person starts feeling achy, fatigued and a little feverish as the bug makes itself at home throughout the body. The whole process from infection to incubation back to health generally takes about two weeks, and for healthy children and adults, is not considered life-threatening. For unhealthy or older people, however, the virus can be deadly.
Because each kiss varies in time and intensity, there is no way of knowing how much kissing sets you up for cellular attack, but experts estimate it takes only 10 viral particles to transfer an infection. So, the longer and more intensely two people kiss, the more likely it is a virus can invade a partner.
While it is true that EBV is easy to transmit from one person to another through kissing, there is usually no recognized illness associated with the infection. Even when Mono does follow, there is complete recovery in a short period.
On the brighter side, Kissing allows prospective mates to taste each other's pheromones for biological compatibility. It is a much stronger chemical reaction than merely sniffing each other. Humans also judge potential mates on the quality of the kiss as a sign of a potential lover's personality and ability to commit. Kissing makes us feel good by causing a release of endorphins in the brain
Therefore, while “kissing disease” is real, kissing is rarely a danger to your health.