Obstructive Sleep Apnea (OSA) is a common sleep disorder characterized by the repeated collapse of the upper airway during sleep, which leads to pauses in breathing and fragmented rest. For many individuals, the severity of these breathing events is directly influenced by body position, a condition known as positional sleep apnea. Positional therapy is a straightforward, non-invasive strategy designed to manage this specific type of OSA by adjusting how a person sleeps. This approach focuses on maintaining a posture that naturally keeps the airway open.
Why Sleeping on Your Back Worsens Apnea
The supine position, or sleeping flat on the back, is the most detrimental posture for individuals with OSA due to the effect of gravity on the structures within the throat. When a person lies on their back, gravitational force pulls the tongue, soft palate, and uvula backward toward the posterior wall of the throat.
This posterior displacement significantly narrows the pharyngeal space, making the airway more susceptible to collapse when the throat muscles relax during sleep. For individuals with positional OSA, the frequency of apnea and hypopnea events (measured by the Apnea-Hypopnea Index, or AHI) can be two to three times higher in the supine position compared to other postures. Avoiding back sleeping is a foundational goal of positional therapy.
The Benefits of Lateral Sleeping
The single best positional remedy for sleep apnea is sleeping on one’s side, known as the lateral position, because it fundamentally changes the mechanical forces acting on the airway. When the body is turned laterally, gravity pulls the tongue and soft tissues forward or to the side, away from the back of the throat. This action stabilizes the upper airway and prevents gravitational collapse, resulting in a significant reduction in the frequency and severity of breathing interruptions.
Avoiding the supine position has been shown to reduce the AHI by more than half in many patients with positional OSA. This can potentially move them from a diagnosis of moderate apnea to a mild or even normal range. The anatomical change provides a larger minimal cross-sectional area for air to pass through, which is particularly beneficial for those whose apnea is driven by physical obstruction.
Sleeping on the left side may offer digestive advantages, as it can help reduce symptoms of acid reflux and heartburn by placing the stomach below the esophagus. Conversely, for patients with certain heart conditions, sleeping on the right side may be preferred, as it can lower heart strain and reduce heart rate. Both lateral positions achieve the primary goal of positional therapy by countering the gravitational pull that causes airway obstruction.
Tools and Techniques to Stay on Your Side
Successfully maintaining the lateral position throughout the night requires implementing practical strategies. A simple, low-tech option is the “tennis ball trick,” where a tennis ball is sewn into the back of a pajama top or shirt to make rolling onto the back uncomfortable. While inexpensive, this method is often discontinued due to discomfort or sleep disruption.
Specialized pillows, such as large body pillows, wedge pillows, or contoured foam pillows, are a more comfortable alternative. They offer physical support to stabilize the body in the side position. These devices prevent inadvertent rolling and offer a supportive cradle for the head and neck, which optimizes airway alignment. Positional backpacks or belts with foam blocks are also used to physically impede a person from lying flat on their back.
Modern positional therapy often utilizes wearable vibrotactile devices, which are worn around the chest or neck. These devices use sensors to detect when the wearer shifts into the supine position and respond with a gentle vibration. The subtle vibration prompts the sleeper to change position without fully waking them, leading to better long-term adherence. These devices often include an adaptation program to gradually train the user’s body to sleep laterally.
Limits of Positional Therapy
While positional therapy is an effective treatment, it is not a universal solution for all types of sleep apnea. This approach is most successful for individuals with positional OSA, which accounts for approximately 50 to 60 percent of all obstructive sleep apnea cases. In these patients, the therapy directly addresses the primary cause of their breathing events: the anatomical collapse induced by the supine posture.
The therapy is recommended for those with mild to moderate OSA, where the total AHI is below 30 events per hour. For patients with severe OSA, or those with non-positional sleep apnea where breathing events occur frequently regardless of the sleeping position, positional changes alone are insufficient. These cases often stem from anatomical issues that require positive airway pressure (CPAP) therapy or an oral appliance for effective management. Consulting a sleep specialist is necessary to ensure proper diagnosis and to determine if positional therapy should be used alone or combined with other treatments.