In weight loss studies of overweight individuals, those who lose weight show reduced apnea frequencies and improved apnoea–hypopnoea index (AHI). Weight loss effective enough to relieve obesity hypoventilation syndrome (OHS) must be 25–30% of body weight. For some obese people, it can be difficult to achieve and maintain this result without bariatric surgery. Rapid palatal expansion
In children, orthodontic treatment to expand the volume of the nasal airway, such as nonsurgical rapid palatal expansion is common. The procedure has been found to significantly decrease the AHI and lead to long-term resolution of clinical symptoms.Since the palatal suture is fused in adults, regular RPE using tooth-borne expanders cannot be performed. Mini-implant assisted rapid palatal expansion (MARPE) has been recently developed as a non-surgical option for the transverse expansion of the maxilla in adults. This method increases the volume of the nasal cavity and nasopharynx, leading to increased airflow and reduced respiratory arousals during sleep. Changes are permanent with minimal complications. Palatal expansion is a unique treatment in that it is minimally invasive, has lasting changes and requires minimal patient compliance for treatment success. Surgery
Several surgical procedures (sleep surgery) are used to treat sleep apnea, although they are normally a third line of treatment for those who reject or are not helped by CPAP treatment or dental appliances. Surgical treatment for obstructive sleep apnea needs to be individualized to address all anatomical areas of obstruction. Nasal obstruction
Often, correction of the nasal passages needs to be performed in addition to correction of the oropharynx passage.
The  antidepressant desipramine may stimulate upper airway muscles and lessen pharyngeal collapsibility in people who have limited muscle function in their airways.There is limited evidence for medication, but 2012 AASM guidelines suggested that acetazolamide "may be considered" for the treatment of central sleep apnea; zolpidem and triazolam may also be considered for the treatment of central sleep apnea, but "only if the patient does not have underlying risk factors for respiratory depression". Low doses of oxygen are also used as a treatment for hypoxia but are discouraged due to side effects. Oral appliances
An oral appliance, often referred to as a mandibular advancement splint, is a custom-made mouthpiece that shifts the lower jaw forward and opens the bite slightly, opening up the airway. These devices can be fabricated by a general dentist. Oral appliance therapy (OAT) is usually successful in patients with mild to moderate obstructive sleep apnea. While CPAP is more effective for sleep apnea than oral appliances, oral appliances do improve sleepiness and quality of life and are often better tolerated than CPAP. Nasal EPAP
Nasal EPAP is a bandage-like device placed over the nostrils that uses a persons own breathing to create positive airway pressure to prevent obstructed breathing. Oral pressure therapy
Oral pressure therapy uses a device that creates a vacuum in the mouth, pulling the soft palate tissue forward. It has been found useful in about 25 to 37% of people.