CPAP vs. BiPAP: Understanding the Usage Differences

Positive Airway Pressure (PAP) therapy is one of the most widespread treatment methods for sleep apnea patients. Sleep apnea is a severe breathing disturbance in which your breathing frequently pauses during sleep.

Estimated reports from experts suggest that 5% to 10% of the total population is affected by it. If it goes neglected, it can cause insomnia, loud snoring, and gasping and lead to undesirable heart problems or high blood pressure.

Continuous Positive Airway Pressure (CPAP) and Bi-level Positive Airway Pressure (BiPAP) are the two most common forms of PAP treatment. Both these therapies work similarly through machines that aid air-passing to the breathing passage and lungs.

Despite similarities, they do have some differences, which means that each holds unique benefits and downsides to reflect on. In this article, we break down the key differences between the two methods, their attributes, indications, and circumstances where they can be best operated.

However, to understand the differences between CPAP and BiPAP, it is necessary to first understand the functioning of a PAP device and its effects on the breathing levels of the affected individual.

How PAP Devices regulate breathing?

OSA or Obstructive Sleep Apnea (1)(2), regardless of the severity levels, is a condition that restricts involuntary airflow into the nasal airway, thereby leading to erratic sleeping cycles, night gasping, and breathing difficulties at night.

To mitigate these issues, doctors recommend PAP or Positive Airway Pressure devices to facilitate easier breathing by incrementally pushing pressurized air into the concerned air chamber of the body.

However, breathing isn’t only about the inhalation and you also need to breathe out against the pressurized air to ensure that the lungs get requisite levels of oxygen. This is where a BiPAP device comes into the play as unlike a CPAP on Continuous Positive Airway Pressure device, it focuses on something called the Bi-level therapy.

CPAP Therapy

Continuous Positive Airway Pressure (CPAP) Therapy is a standardized treatment for Obstructive Sleep Apnea (OSA), a breathing problem in which your lungs don’t receive adequate air. The CPAP machine pumps air at a single pressure level to keep your breathing passage open while you are sleeping.

The steady flow of air is provided through a face mask, and the level of pressure setting is only prescribed by a doctor based on the requirement and risk factors of the patients.

Effective air pressure can also avert loud snoring and ought to decrease the apnea-hypopnea index (AHI).

BiPAP Therapy

Bilevel Positive Airway Pressure (BiPAP) Therapy is a standard treatment for patients suffering from Central Sleep Apnea (CSA) and Complex Sleep Apnea, or COPD, another sleep-related breathing disorder in which your brain fails to send appropriate signals to the muscles that handle the breathing mechanism.

So If you are suffering from a more severe version of sleep apnea, exhaling against the singular air stream becomes overwhelming and exceedingly difficult.

This is where a BiPAP machine comes into the mix as it comes with a dual-pressure setting i.e. one for assistance during inhalation and the other for exhaling at a lower pressure

A BiPAP machine looks identical to a CPAP machine but differs in the mechanism. Unlike the CPAP device, a BiPAP machine discharges air at two different pressure levels. The patient can inhale at a higher pressure level while exhaling against a lower pressure.

BiPAP can also prevent aerophobia (air swallowing) and claustrophobia. It may be helpful for those who aren’t accustomed to CPAP devices.




What it is

A treatment for sleep apnea that uses a machine to deliver a constant flow of air

A treatment for sleep apnea that uses a machine to deliver two levels of pressure

How it works

It delivers a constant flow of air through a mask to help keep the airways open

It delivers a higher pressure when the person inhales and a lower pressure when the person exhales




Pressure Range

4 to 20 cm H2O

4 to 30 cm H2O

Recommended for

CPAP machines are recommended for patients having Obstructive Sleep Apnea (OSA) 

BiPAP machines are recommended for patients having Central Sleep Apnea (CSA) and Complex Sleep Apnea, or COPD

Mask type

Three types - Full face, Nasal, and Nasal Pillow

Three types - Full face, Nasal, and Nasal Pillow

Ease of use

A CPAP has a hose attached to the mask or nosepiece to pump steady and stable air pressure to help you breathe while you are asleep.

A BiPAP delivers air pressure at two different levels and many people find it easier to employ than CPAP ones since it delivers lower pressure during exhalation. 


Patients using CPAP machines find it difficult to exhale at higher pressures; hence they are less comfortable.

BiPAP machines allow patients to effortlessly exhale and breathe more comfortably by reducing the air pressure level during exhalation. Hence, BiPAP machines are more comfortable. 


$250 to $1,000

$1,000 and $3,000

Effectiveness in treating sleep apnea

CPAP machines are more effective to treat Obstructive Sleep Apnea (OSA) 

BiPAP machines are more effective to treat Central Sleep Apnea (CSA) and Complex Sleep Apnea, or COPD


Depends on the insurance policy but mostly covered by private health insurance companies. 

May be covered by an insurance company or Medicare center if you meet certain conditions

Significance of a BiPAP

In case you use a BiPAP machine, it becomes easier to regulate breathing even when you are fast asleep. As there is a two-way pressure regulation to account for, the throat and nasal cavity or airway do not collapse regardless of the process. Therefore, it wouldn’t be wrong to infer that BiPAP usage is way more comfortable than a CPAP.

Besides, a BiPAP machine, unlike a CPAP unit, isn’t meant just for treating OSA. Instead, you can use the Bi-PAP machine if you have lower blood oxygen levels to account for. Moreover, individuals with congestive heart ailments are more likely to resort to Bi-PAP devices followed by patients suffering from neuromuscular and lung disorders.

What Is the Difference between CPAP and BiPAP?

Both CPAP and BiPAP are types of positive airway pressure (PAP) that direct air into the upper breathing passage and lungs while you are asleep. The portable machine produces pressurized air and pushes it into the airway of the patient through a hose or face mask. Thus preventing contraction or collapsing during sleeping hours.

It wouldn’t be wrong to state that a BiPAP device fixes the side-effects and inadequacies of a CPAP device. For instance, if the CPAP pressure for a patient is on the higher side, breathing out can still be a challenge even with the RAMP feature turned on. This means your body doesn’t get the perfect avenue to push the residual air out of the airway.

Both these machines were built for similar causes, but they differ in working principles, indications, pricing, and insurance coverage.

1. Pressure

The air pressure settings of a patient depend on the type of PAP therapy that has been recommended by the doctor.

A CPAP machine pumps air at a fixed pressure only, whereas a BiPAP machine provides air at two distinct pressure levels. The pressure setting in a CPAP machine is adjustable and ranges between 4 to 20 cmH2O. BIPAP machine, on the other hand, provides inhalation-positive airway pressure (IPAP) and exhalation-positive airway pressure (EPAP) at a range of 4 to 30 cmH2O.

2. Indications

CPAP Indications

CPAP may be the ideal option if you have any one of the following:

  • Tachypnoea (Rapid breathing)
  • Respiratory Acidosis
  • Pulmonary oedema
  • Premature Apnoea
  • Recent extubation
  • Atelectasis
  • Transient Tachypnoea of the newborn (TTN)
  • Tracheomalacia

BiPAP Indications

BiPAP may be the ideal option if you have any one of the following:

  • Acute or acute-on-chronic respiratory acidosis secondary
  • Exacerbation of COPD where the pH range is 7.35 or below
  • Endotracheal intubation
  • Cardiogenic pulmonary edema

BiPAP may be a good option for mechanical ventilation if the patient’s breathing rate is not deteriorating immediately.

3. Insurance Coverage

The insurance coverage for CPAP therapy varies, and it simply depends on your insurance policy. But mostly, it is covered by private health insurance companies. It is essential to consult with the insurance company beforehand and clarify coverage for CPAP supplies and accessories. However, a Medicare recipient may be offered a 3-month trial period of CPAP therapy that comprises a CPAP machine and supplies like masks and surrogate filters. After a check-up and review of the data, the insurance company may go on with coverage for their CPAP therapy.

The insurance coverage for BiPAP therapy may only be covered by the insurance company or Medicare center if you meet certain conditions. For example, the coverage for your BiPAP therapy may be discarded unless you prove your intolerance for CPAP therapy or CPAP fails to treat your sleep apnea.

4. Comfort

In case you are suffering from a severe case of OSA and using CPAP as the go-to machine, consider using an optional humidifier for additional comfort. However, if the pressure increases, involuntary exhalation might be exceedingly difficult to initiate and this is where a BiPAP machine becomes all the more relevant by cutting out gasping and air gulping, completely. As there are two pressure settings to rely on Aerophagia or air swallowing is duly taken care of

5. Usage

While CPAPs are mostly aligned to sleep disorders and apneas, BiPAP usage takes an all-inclusive form courtesy of the additional perks concerning AHI balance, breathing monitoring, and more.

6. Pricing

The cost of a CPAP machine can range anywhere from $250 to $1,000.

BiPAP machines, on the other hand, carry additional sensors and settings, and their design is more complex than a CPAP machine. Most BiPAP machines cost between $1,000 and $3,000.

Maintenance of CPAP and BiPAP Machines

The water chamber needs to be emptied every day. Wipe the mask and headgear with warm soapy water daily. The filters need to be replaced every 6 months. Change the mask and headgear twice a year. Get a new tube every 1 or 2 years. Replace the humidifier chamber as and when required, generally within 1-3 years.

Upsides and Downsides of CPAP Therapy

Here's the Upsides

1. Improves Life Expectancy 

Sleep apnea can be fatal if neglected. Using a CPAP device can aid you in treating sleep apnea and prevent heart attack and chest pain. It improves the quality of the health system and helps you lead a longer and healthier life.

2. Better Sleep Cycles

Sleep apnea leads to poor sleep cycles and daytime sleepiness due to lack of sleep at night. But when you use a CPAP machine, your body automatically feels better. It aids you in experiencing better sleep cycles and fixes daytime tiredness.


1. Uncomfortableness

The level of discomfort while wearing the machine is the biggest downside. The disturbance of the mask on the face and strap around the head is indeed not something that people are used to.

2. Noisy Machine

CPAP machines operate at below 30 decibels. However, patients sometimes find it disturbing due to the sound of the motor.

3. Dry Mouth

The machine discharges dry air into the mouth all night. Hence, patients experience dry mouth when they wake up in the morning. This can be prevented by adding a heated humidifier to the machine.

4. Bloating and Gas

The CPAP devices gulp air during the night, which can cause tight bloating and gas. This can be managed by regulating the pressure settings.

Upsides and Downsides of BiPAP Therapy


1. Alternate Airflow

The biggest advantage of BiPAP machines is their ability to supply alternating airflow pressure. The patient can breathe in at a higher pressure level and breathe out against a lower pressure. It can notice the breathing pattern of the patient and then regulates the pressure settings to match the same pattern.

2. Prevents Neuromuscular Diseases

A BiPAP machine is ideal for people who suffer from neuromuscular disease. It provides standardized breathing assistance, which CPAP lacks.

3. Ideal for Cardiopulmonary Disorder and Acute Sleep Apnea

The additional features of BiPAP machines are proven to be effective against cardiopulmonary disorders. It perfectly balances the level of carbon dioxide and oxygen all day long and hence is highly suggested for patients having moderate to acute sleep apnea.


1. Expensive

BiPAP machines having additional supplies and mechanisms are more expensive than CPAP ones.

2. Usage

The BiPAP machine can’t be operated unless the patient fails to cope with the CPAP device.

3. Central Sleep Apnea

In BiPAP machines, the air for inhalation (IPAP) is considerably higher than the air used when exhaling (EPAP), which can enlarge the lung volume. Thus, the patient who was the machine to cure obstructive sleep apnea (OSA) may develop central sleep apnea (CSA).

CPAP Vs. BIPAP– Which One is Better?

Both CPAP and BiPAP machines are highly effective in aiding sleep apnea. However, BiPAP machines are more advanced and possess high-end pressure settings, which CPAP lacks.  While CPAP is still a standard choice for OSA or Obstructive Sleep Apnea, BiPAPs are more relevant to other conditions that can compromise the existing blood oxygen levels within the body. CPAP delivers a continuous stream of air at a single, constant pressure, while BIPAP delivers air at two different pressures – a higher pressure for inhalation and a lower pressure for exhalation.

This can make BIPAP more comfortable for some people, as the pressure changes can feel more natural. Additionally, BIPAP may be more appropriate for certain types of sleep apnea or for people with underlying medical conditions that make it difficult to tolerate high levels of air pressure.

Regardless of the benefits and perks offered by a BiPAP machine in regard to sleep apnea, ALS, neuromuscular disorders, and more, it is always advisable to consult with a physician for getting the most out of any given machine.,