Sleeping on your back and not your side or stomach after a PDO thread lift is a critical PDO Thread aftercare tip. That's because stomach and side sleeping can place unnecessary and potentially damaging pressure and friction on the face and even interfere with healing. Therefore, avoiding sleeping on your side for at least one week post-treatment is often recommended. To sleep more comfortably, try propping your head up with an extra pillow, which will help minimize any swelling.