CPAP vs. BiPAP: What's The Difference? (2024)

CPAP machines are devices for people with sleeping disorders, such as obstructive sleep apnea and central sleep apnea, which both interrupt breathing during the sleep cycle. They are designed to keep airways open while individuals sleep. “CPAP works by delivering pressurized air through a tube and mask which keeps the upper airways from collapsing during sleep,” explains Chelsie Rohrscheib, Ph.D., a sleep specialist at Wesper, a digital at-home sleep lab solution based in New York City.

“Modern machines have the ability to store the information of the sleep patterns on a memory chip. Some machines are stationary and are placed on the nightstand and there are smaller machines that one is able to travel with, that are easy to place anywhere. Some machines have humidifiers that require water and are attached to the machine. All of the machines are able to work outside the US, and are able to adjust to different electrical currents found in Europe and Asia,” explains Dr. Alexander Vaiman, D.D.S., a dentist at New York Family Dental Arts in New York City who specializes in sleep apnea treatments.

“All CPAP devices usually involve a nose or a nose-and-mouth mask (depending on individual facial features of the patients), which is attached to the machine with a flexible hose about five to six feet long. Pressurized air is delivered through the nose mask so that people can breathe easier and sleep better,” says Dr. Vaiman.

Who Needs a CPAP Machine?

Health care providers prescribe CPAP machines for individuals who have been diagnosed with sleep apnea or show signs of the condition, such as snoring, feeling exhausted upon waking, daytime sleepiness and unusual breathing patterns, Cheyne-Stokes respirations, which involve fast, shallow breathing followed by heavy breathing and periods without any breathing at all.

Bilevel positive airway pressure (BiPAP) machines are similar to CPAP machines but deliver a higher pressure when a person inhales and a lower pressure when they exhale. “The high pressure on inhalation keeps the airways open while the low pressure on exhalation is much easier to breathe against than [the pressure delivered through] the CPAP. Thus, many people find BiPAP more comfortable than CPAP,” notes Dr. Rohrscheib.

A BiPAP machine’s settings can be preset so its pressure levels won’t change. “The
new modern machines are able to automatically adjust the pressures during the night depending on the patient’s breathing, moment to moment,” says Dr. Vaiman.

Who Needs a BiPAP Machine?

“A BiPAP machine is normally prescribed for patients with severe sleep apnea who stops breathing more than 30 times per hour and those who have more advanced health problems like cardiopulmonary disease, chronic obstructive pulmonary disease (COPD), coronary artery disease and congestive heart failure,” explains Dr. Vaiman.

“The main difference between CPAP and BiPAP is the variability of the pressures. BiPAP offers more control over the inhalation and exhalation pressures. CPAPs do not control exhalation pressure like BiPAPs do,” explains Dr. Vaiman.

Whether an individual needs a CPAP or BiPAP machine depends on their particular diagnosis, health conditions, needs and preferences. CPAP is considered a first-line treatment for people who have sleep apnea, according to Dr. Rohrscheib. “CPAP is one of the most efficient therapies, with an 80% to 100% success rate,” she adds.

Dr. Vaiman explains that someone who has healthy lungs will likely need a CPAP. Someone with severe sleep apnea, however, will generally be prescribed a BiPAP machine. “Generally, people do very well with these machines and get used to them with some learning curve. But there are some CPAP failures, and some people just cannot get used to the machines, masks, noises, hoses, etc.,” he says.

Those who can’t find success with a CPAP may want to try a BiPAP, which features two pressure settings, including a lower pressure when you breathe out, that can make it easier for you to exhale. Consult with your sleep care team to determine which type of therapy and machine is best.