Obstructive sleep apnea (OSA) is a disorder in which the upper respiratory tract is closed repeatedly during sleep. Treatment of OSA includes continuous positive airway pressure (CPAP), intraoral devices, and upper respiratory tract surgery, among which CPAP is known as the most effective treatment method. However, even in the case of CPAP, adherence rates during long-term follow-up are lowered considerably due to inconvenience of wearing, and low adherence rates limit its therapeutic effect. Therefore, studies have been carried out to confirm the effect of lifestyle modification which corrects modifiable risk factors of OSA, such as obesity. The aim of this study was to examine the effects of weight loss and aerobic exercise to improve the severity of OSA, and to examine the effect of drinking and smoking on OSA. In consideration of the difficulty of modifying one's lifestyle through traditional individual counseling, we propose the use of smart devices in the management of patients' lifestyles.