Two common symptoms of snoring are pauses in breathing during sleep and daytime sleepiness. People may feel tired because their sleep is interrupted by gasping, coughing, wheezing, and frequent trips to the bathroom. A lack of restful sleep contributes to depression, anxiety, mood swings, and poor concentration at work or school. Snoring throughout the night may lead to morning headaches, an upset stomach, dry mouth, or a sore throat. Long-term symptoms of snoring include tooth decay, high blood pressure, or chest pain.

The sound of snoring is produced by vibrations. The throat opens and closes during inhalation and exhalation, and tissues vibrate as air passes through. Muscles in the throat relax during sleep, and the tongue falls backward. This narrows the air passage and increases vibration. Snoring becomes louder in proportion to increasing vibrations. Apnea, a cessation or pause in breathing, occurs when muscles in the throat collapse completely.

Snoring is often caused by too much tissue in the throat or nasal areas. Being overweight leads to additional bulk in the throat and nasal passages which results in snoring. This even applies to people who never snored before gaining weight. Weight gain is frequently associated with loss of muscle tone that can result in relaxed throat muscles.

Snoring is a sign of obstructive sleep apnea if it is interrupted by pauses in breathing and snorts or gasps as the sleeping person inhales. A person with sleep apnea experiences brief pauses in breathing up to 30 times every hour. The brain responds to decreasing blood oxygen levels by prompting a surge of adrenaline. The adrenaline pulls a person out of deep sleep to take a breath. The sleeper gets very little deep, restful sleep, while constant adrenaline surges and fluctuating oxygen levels put stress on the heart and cardiovascular system.

Muscle relaxants, alcohol, prescription antipsychotic drugs, and medications for insomnia or anxiety are known to cause and worsen snoring. These medications relax the muscles in the throat and make it harder for people to rouse from a deep sleep. Opiates have similar effects and relax muscles throughout the respiratory system. Anti-histamines are an exception and may relieve snoring. They cause drowsiness and are often prescribed for insomnia, but they also reduce congestion.

Abnormal anatomical structures in the throat and nose can cause chronic snoring. A deviated septum occurs when the wall between the nostrils shifts to one side. Nasal polyps are soft growths that sometimes develop in the sinuses or inside the nose itself. Enlarged or inflamed tonsils and adenoids also obstruct the airway. Snoring is sometimes increased or relieved by changing positions. Sleeping while lying flat can increase snoring, while too much elevation from pillows or supportive devices pushes the head forward and constricts the airway.

The most common cause of occassional snoring is nasal congestion. Allergies, illness, and air pollution cause nasal congestion. Excessive mucus clogs nasal airways and leaves less space for air to pass. Breathing obstruction and snoring can occur without obvious mucus. Sinus irritation does not always produce excessive mucus. Chronic sinus irritation or infection causes the tissues in the sinuses and air passage to swell. Swelling and possible build-up of mucus in the sinuses worsens when people lie down to sleep. Signs of sinus congestion are headaches around the eyes and an unusual or foul taste upon waking.

Most children snore once in a while, but chronic snoring could indicate a more severe health problem. Allergies, asthma, enlarged tonsils, and the common cold are the usual causes of childhood snoring. Tonsils occupy a disproportionately large area of a child's throat. Swollen tonsils can block the airway and interfere with breathing. Children can also develop sleep apnea.

Snoring increases with age for several reasons. People tend to become less active as they age, which puts them at risk of losing muscle tone and gaining weight. Women have lower levels of estrogen after menopause. This leads to softer muscles in the upper airways. People usually take more medications as they get older as well, so there is always the increased risk of taking medication that worsens snoring.