In this video, Dr. K K Aggarwal, Padma Shri Awardee, Editor-in-chief, IJCP Publications, will explain about oxygen desaturation index. The oxygen desaturation index (ODI) i s typically measured as part of standard sleep studies, such as a diagnostic polysomnogram. It is done in person’s with heavy snoring with sleep obstructive apnea. It is in how many hours the person develops a oxygen desaturation level of more than 4 %. He will further explain the evaluation of such patients.