Generally speaking, both CSR and periodic breathing are usually thought to be a result of some other underlying medical condition. Both of these abnormal breathing patterns are most commonly seen in patients who have suffered a stroke, congenital heart failure, brain tumors, or damage to their brain, spinal cord, or brain stem which affects the brain's respiratory centers, located in the medulla oblongata at the bottom of the brain stem.

In addition, it could also be a result of morphine intake or carbon monoxide poisoning, and is also present in patients with toxic metabolic encephalopathy, a degenerative neurological disorder caused by exposure to certain organic toxins. However, it seems that these aren't the only possible causes, as both of these conditions can also be a result of sudden, acute exposure to extremely high altitudes, usually over 15,000 feet above sea level. In cases such as this, the majority of people only experience periodic breathing, instead of full blown CSR. These changes in respiratory rates are due to the lower levels of oxygen in the air, which result in cycles of hyperventilation followed by hypoventilation.