Obstructive sleep apnea (OSA) is one of the most common sleep disorder. There are numerous conditions that are related to OSA, such as diabetes, cardiovascular diseases, and metabolic syndrome. If the patient with OSA have large tonsils, soft and largened uvula or flacid soft palate, one might benefit from operative treatment of OSA. The aim of our study is to find out whether an operative treatment is effective in mild OSA patients with carefully assessed anatomical predispositions. Our ultimate goal is to evaluate the effects of operative treatment in mild OSA itself and in the diseases related to OSA. We measure the cardiovasculary functions, symptoms, postoperative recovery, antropometry, laboratory tests, the quality of life, the quality of sleep and the inflammatory system in sleep apnea before and after the surgery.