Sleep-related hypoventilation is a breathing-related disorder that interrupts normal sleep. This condition may be diagnosed when all other sleep disorders have been ruled out, though it may appear simultaneously with other sleep disorders. Breathing is restricted in someone with sleep-related hypoventilation, leading to low levels of oxygen or elevated levels of carbon dioxide in the blood. Sleep-related hypoventilation can occur independently or, more commonly, with other medical or neurological disorders, substance abuse, or even the routine use of prescribed medications.
Sleep-related hypoventilation can occur in anyone, at any age, even in babies and young people. Because many different underlying conditions can contribute to sleep-related hypoventilation, the signs and symptoms can vary from person to person. The most common symptoms include daytime sleepiness, frequent awakenings during sleep, morning headaches, insomnia, stomach problems, faintness, difficulty breathing, and reduced exercise capacity. A significant number of people with sleep-related hypoventilation experience few or no symptoms, or have only mild symptoms in early stages, and may not realize they have a potentially progressive condition. Early stage sleep-related hypoventilation can progress to a more serious chronic hypoventilation disorder, and lead to more serious health problems, including heart failure, respiratory failure, and brain and blood disorders.
Multiple factors can lead to sleep-related hypoventilation, including underlying medical, environmental and genetic circumstances. Breathing can slow down following the use of medications and other substances that suppress the central nervous system, such as benzodiazepines, opiates, and alcohol. Neuromuscular and chest wall disorders can restrict breathing through impairment of respiratory muscles. Most commonly, sleep-related hypoventilation is associated with another medical condition, such as asthma or another pulmonary disorder, hypothyroidism, or obesity, which reduces lung volume and makes breathing more difficult in general.
As a first step toward appropriate treatment, a blood gas test may be used to measure the levels of carbon dioxide and oxygen in the blood. A sleep study may also be performed and used to diagnose sleep-related hypoventilation. This overnight study, also called polysomnography, involves monitoring brain waves, the oxygen level in the blood, heart rate, breathing, and other factors during sleep.
Sleep-related hypoventilation is typically treated by addressing any underlying conditions that may be causing hypoventilation, such as a medical condition or substance use. For instance, in some cases, weight loss may be advised, treatment may be prescribed to restore hormone levels in those with hypothyroidism, or medications known as respiratory stimulants may be used to treat narrowing of airways that can result from drug or alcohol use. Improving these conditions generally helps improve the symptoms of sleep-related hypoventilation. If sleep apnea or another sleep disorder is also present, use of positive airway pressure devices, known as CPAP or BPAP machines, may be required to continually feed oxygen into the lungs while sleeping.