National Sleep Foundation

Chapter 3: Sleep-Related Breathing Disorders

What are Sleep-Related Hypoventilation Syndromes (SRHS)?

All Sleep-Related Hypoventilation Syndromes are characterized by abnormal ventilation and gas exchange that significantly worsens, or may only be present, during sleep. These abnormalities result in increased blood carbon dioxide (CO2) levels (hypercapnea) and are often associated with low blood oxygen concentrations (hypoxemia).2

There are two sub-types of SRHS:

  • SRHS may be primary, possibly related to blunted central or peripheral chemo-responsiveness, or due to a congenital condition.
  • SRHS may also be comorbid with certain medical conditions that cause the impairment of gas exchange, such as Chronic Obstructive Pulmonary Disease (COPD) and emphysema; depression of the central respiratory drive (e.g., opioid-induced); or other neurologic, neuromuscular, or chest wall disorders or abnormalities that impair a person’s ability to breathe.3


  1. Casey, K., Cantillo, K., and Brown, L., Sleep-related hypoventilation/hypoxemic syndromes, Chest;131,6:1936-1948, 2007.
  2. Gozal D, Congenital central hypoventilation syndrome: an update. Pediatr. Pulmonol. 1998;28:273-282.
  3. Thorpy M, “Classification of Sleep-Related Breathing Disorders,” in Kryger M, Roth T, Dement W (ed.), Principles and Practice of Sleep Medicine (5th Edition), St. Louis: Elsevier Saunders, 2011, pages 680-693.