Allergies can inflame the nasal passages, sinuses, and airways of the lungs, and commonly cause or contribute to snoring. Data collected from people with allergic rhinitis (stuffy nose)^{6, 7} and asthma^{8, 9} show that these people are more likely to be snorers than are nonallergic people. In addition, two preliminary studies have found that when snoring is treated using a continuous positive airway pressure device, an instrument primarily used to treat sleep apnea, nighttime asthma attacks decrease.^{10, 11} Children who snore are also more likely than other children to have allergies,¹² and one preliminary study found that more than half of children with allergies are snorers.¹³ One researcher reported that children with allergy symptoms, including snoring, commonly have food sensitivities. Although little more is known about food sensitivities and snoring, it may be helpful to test for food sensitivities.¹⁴ The possibility of asthma and allergies should therefore be considered in people who snore.

A number of studies have found an association between snoring and heart disease. High blood pressure and coronary artery disease have been correlated with snoring in both men and women, and the correlation is stronger in people with normal weight.^{15, 16, 17, 18} In women, snoring is more common after menopause, and is strongly associated with high blood pressure in women around the age of menopause.^{19, 20} Researchers suggest that, with such a strong correlation, it is important to screen for hypertension and heart disease in people who snore.²¹

Obesity and lack of physical activity are commonly associated with heavy snoring.^{22, 23} Even in children, obesity may be linked to snoring and sleep disorders.²⁴ One study found that obese men who snore were significantly more likely to develop diabetes over a ten-year period than were obese men who did not snore.²⁵ Snoring is clearly a problem that should be addressed in obese men, and increasing physical activity and weight loss are widely recommended.^{26, 27, 28} A preliminary trial found that weight loss was more important in reducing snoring than either changes in sleep position or use of a nasal decongestant spray.²⁹ In a report by the U.S. Army, weight control and physical training was advised to reduce the severity of snoring and sleep apnea, and in one presented case, full recovery from severe snoring was achieved with weight loss and use of a continuous positive airway pressure device.³⁰ Two other cases have been reported in which combined weight loss and use of a continuous positive airway pressure device resulted in full recovery from snoring and sleep apnea.³¹

Smoking increases the likelihood of snoring because of its effects on the nasal passages and sinuses.³² In addition, nicotine may cause sleep disturbances that result in more snoring.³³ Men are more likely to snore as they age, but one study found that smoking increases the likelihood of snoring particularly in men under the age of 60.³⁴ A sleep study found that heavy smokers are more likely to snore than are moderate and light smokers, and that people who have quit smoking are no more likely to snore than are people who have never smoked.³⁵ Teenagers who smoke have also been found to be more likely to snore than non-smoking teenagers, and that snoring was associated with frequent nighttime wakening and daytime sleepiness.³⁶ Exposure to environmental smoke, or “second-hand smoke,” has been shown to increase the likelihood of snoring in children.^{37, 38} Smoking cessation and elimination of environmental smoke exposure are therefore important in the treatment of snoring.

It has long been thought that consumption of alcohol contributes to snoring, and at least one study has found this to be true,³⁹ but several studies have been unable to verify this link.^{40, 41, 42}