Snoring is the act of breathing through the open mouth in such a way as to cause a vibration of the uvula and soft palate, thus giving rise to a sound which may vary from a soft noise to a loud unpleasant sound. This most commonly occurs during sleep.

The cause of snoring is some kind of blockage in the breathing passage.

Those blockages can be of many kinds—here are just a few:

Tongue falling into the throat.
Allergies.
Throat weakness causing the throat to close during sleep.
Mispositioned jaw, often caused by tension in muscles.
Fat gathering in, and around, the throat.
When the airflow in the breathing passage becomes irregular due to a blockage the soft palate may start flapping. This flapping of the soft palate is what makes the snoring sound.

Numerical statistics on snoring are often contradictory, but at least 30% of the adult population and perhaps as many as 50% of people in some demographics snore.

Most of the time snoring is not a health risk to the snorer, but snoring resulting from a significant obstruction of the breathing passage can be an indication of the potentially life-threatening disorder sleep apnea.

Even if snoring may not be detrimental to the snorer, it can cause the snorer's bedmate or roommates to lose sleep. Being sleep deprived can lead in some cases to life-threatening problems for the person and those around them. Also, studies have shown that there is a psychological component in snoring which causes discomfort in any listener, depending on the loudness, tone, frequency, and other auditorial attributes of the snore. Studies have shown that there is a direct inverse relationship between snoring and frequency of sexual activity between married partners, meaning that there is generally less sexual activity if one of the partners is a heavy snorer.

Snoring is usually an involuntary act, but may also be produced voluntarily.

According to Dr. William C Dement, of the Stanford Sleep Center, anyone who snores and has daytime drowsiness should be evaluated for sleep disorders.

The loudest snore on record was 93 decibels.

Cures

Snoring cures almost all revolve around clearing the blockage in the breathing passage. This is the reason snorers are advised to lose weight (to stop fat from pressing on the throat), to stop smoking (smoking weakens and clogs the throat), and to sleep on their side (to prevent the tongue from blocking the throat).

Surgery is one option to cure snoring (for example a uvulopalatopharyngoplasty); dental appliances such as a mandibular advancement splint are another. There are many devices such as nose clips to keep the nose open and jaw mechanics to keep the jaw in the right position. Different aids work for different people. According to the British Medical Journal, playing the didgeridoo can also help.