Obesity Hypoventilation Syndrome (OHS) is a condition that occurs in individuals with severe obesity, leading to inadequate breathing during sleep. This results in low oxygen levels and high carbon dioxide levels in the blood, which can cause daytime sleepiness, fatigue, and difficulty concentrating. People with OHS often experience disrupted sleep patterns and may develop obstructive sleep apnea. Treatment typically involves weight loss, lifestyle changes, and sometimes the use of devices like continuous positive airway pressure (CPAP) machines to help maintain proper breathing during sleep.