Anyone recently diagnosed with a sleep breathing disorder has probably heard both terms thrown around by doctors, pharmacists, and well-meaning relatives: CPAP and BiPAP. The two machines look similar, sit on the same bedside table, and both use a mask connected to a hose, but they work quite differently and are prescribed for different situations. Understanding the distinction before you buy or rent one can save both money and discomfort.
How CPAP Works
A CPAP (Continuous Positive Airway Pressure) machine delivers a single, constant stream of pressurised air through the night. That steady pressure keeps the airway from collapsing, which is the root cause of obstructive sleep apnea in most patients. Because the pressure stays fixed at whatever level a sleep study determines, CPAP machines are simpler mechanically and generally cost less than BiPAP units in India, with entry-level auto-adjusting models available from roughly ₹35,000 and premium models going upward of ₹90,000.
Who CPAP Suits Best
- Patients with straightforward obstructive sleep apnea (mild to moderate)
- People who tolerate constant airflow pressure comfortably
- First-time users starting therapy after a diagnostic sleep study
How BiPAP Differs
BiPAP (Bilevel Positive Airway Pressure) machines deliver two different pressure levels — a higher one during inhalation and a lower one during exhalation. This makes breathing feel more natural for patients who find constant CPAP pressure hard to exhale against, particularly those with more severe apnea, obesity hypoventilation syndrome, or coexisting conditions like COPD. Because BiPAP machines have more complex circuitry to sense and switch between two pressures in real time, they typically cost more, usually starting around ₹55,000 and going well beyond ₹1.5 lakh for models with advanced modes like ST (spontaneous/timed) for patients who need backup breaths.
Who Typically Needs BiPAP
- Patients with severe obstructive sleep apnea who struggle with CPAP pressure
- People with overlapping COPD and sleep apnea (overlap syndrome)
- Patients with central sleep apnea or neuromuscular conditions affecting breathing
- Those who need a backup respiratory rate if breathing becomes irregular
Comparing the Two at a Glance
| Feature | CPAP | BiPAP |
|---|---|---|
| Pressure delivery | Single fixed pressure | Two alternating pressure levels |
| Typical condition treated | Mild to moderate OSA | Severe OSA, overlap syndrome, central apnea |
| Comfort for exhalation | Can feel harder to exhale against | Generally easier to exhale |
| Approximate price range (India) | ₹35,000–₹90,000 | ₹55,000–₹1,50,000+ |
| Machine complexity | Simpler, fewer sensors | More advanced pressure-switching electronics |
Neither machine should be chosen without a proper diagnostic sleep study, since the prescribed pressure settings and machine type depend entirely on the severity and pattern of apnea events recorded overnight. Many patients assume BiPAP is simply the "upgraded" version of CPAP, but that is not accurate — a person with straightforward mild apnea will usually do just as well, or better, on a standard CPAP and save considerably on both the machine cost and ongoing mask supplies.
Understanding Sleep Apnea Before Choosing Equipment
Before deciding between the two machines, it helps to understand what actually causes sleep apnea and the different types a sleep study might reveal. If you want to read the full guide on causes, types, and risk factors, it lays out the difference between obstructive, central, and mixed apnea in more detail than a typical hospital consultation allows time for.
For general reference on sleep and breathing disorders, the NHS overview of sleep apnoea is a reliable, non-commercial resource that explains diagnosis pathways and treatment options in plain language.
Takeaway: let your sleep study results and doctor's prescription — not price or brand marketing — decide between CPAP and BiPAP, since using the wrong machine type can mean paying more for a device that doesn't actually treat your specific breathing pattern effectively.