Pulse Oximeter Bias: 2026 Equity in Pain Care

A pulse oximeter can read a normal 95% oxygen saturation on a patient with darker skin who is actually hypoxic and needs immediate help, a dangerous flaw in a device we use everywhere. This pulse oximeter bias means we have to rethink how we use and trust our equipment, not just in hospitals but even in procedures like professional waxing, where a client’s reported pain or discomfort has to be taken over what a machine might say.

The Hidden Disparity: When Technology Fails Darker Skin

Medical devices have a long history of being designed for a narrow slice of the population, causing real health disparities, and the common pulse oximeter is a perfect example. It’s on every crash cart and in every clinic, but it simply doesn’t work as well on people with darker skin. The issue is baked right into its physics.

A pulse oximeter clips on a fingertip and shoots two kinds of light, red and infrared, through the skin to measure your blood. The whole idea is that hemoglobin carrying oxygen absorbs light differently than hemoglobin that isn’t, and the device calculates the saturation based on that difference. The problem is melanin, the pigment in darker skin, also absorbs light, especially in the red spectrum, which confuses the sensor and makes it harder to get a clean reading on the hemoglobin. This interference can artificially inflate the oxygen saturation number, so a person with darker skin might be in a state of hypoxemia (dangerously low oxygen) while the machine shows a reading that looks totally fine.

This isn’t just a theory. A 2020 study in the New England Journal of Medicine put numbers to the problem, finding that pulse oximeter readings were way less accurate in Black patients than in White patients, especially once true saturation dropped below 92%. A follow-up report in JAMA Internal Medicine in 2021 confirmed it, showing oximeters were overestimating oxygen levels by 1% to 5% in patients with darker skin when compared to direct arterial blood gas tests. That kind of error margin isn’t a small thing. It’s a patient safety issue that directly undermines any claim of providing equitable comfort and care.

How Design and Practice Created a Blind Spot

The original pulse oximeters failed on inclusivity. It’s that simple. They were developed and calibrated almost exclusively on light-skinned test subjects, so the algorithms were never built to handle the variations in skin pigmentation that melanin introduces. Because they didn’t have diverse representation in the R&D phase, a major design flaw got baked into a technology that’s now used millions of time a day. The core assumption, that one calibration works for everyone, was just flat-out wrong.

Clinical habits made the design flaw worse. We got too used to just trusting the number on the screen instead of looking at the whole patient. A provider sees a “normal” SpO2 reading and might, quite understandably, dismiss a patient’s own report of feeling short of breath. In that moment, the technology isn’t helping make a diagnosis. It’s actively hiding it for anyone whose skin tone throws off the reading.

Training has been a huge gap, too. Medical and nursing schools teach the basics of how a pulse oximeter works, but the specific problem of how skin pigmentation affects the readings often gets glossed over, if it’s mentioned at all. So you have a generation of well-meaning clinicians who simply don’t know the device has this bias and haven’t been taught how to work around it.

Fixing the Problem: A Multi-Pronged Strategy

Fixing pulse oximeter bias isn’t just about one device. It’s about changing how we approach patient assessment altogether. We need to attack this with better technology, smarter clinical protocols, and a serious push for education to build a culture of genuinely inclusive pain assessment.

1. Technological Advancements and Enhanced Calibration

Device manufacturers need to step up and build next-gen pulse oximeters that actually work for everyone. This involves using things like multi-wavelength sensors and smarter algorithms that can tell the difference between light absorbed by melanin and light absorbed by hemoglobin. Some companies are already working on this, and the FDA is putting on the pressure with safety communications and calls for more R&D, because they know how serious this is.

In the meantime, we have to do a better job with the gear we already have. Regular calibration and maintenance isn’t a silver bullet, but it helps. Every hospital and clinic needs to have strict protocols for checking and updating their oximeters.

2. Re-emphasizing Clinical Judgment and Complete Assessment

A machine’s reading should never be the final word. Clinicians have to be trained to use the pulse oximeter as just one piece of the puzzle, combining its reading with a full patient assessment. This means actually looking at and talking to the patient, using our own judgment. We should be checking for:

• Visual Cues: Observing for signs of cyanosis (bluish discoloration of skin, lips, or nail beds), though this can be harder to detect on darker skin.
• Respiratory Effort: Assessing breathing rate, depth, and the use of accessory muscles.
• Patient-Reported Symptoms: Actively listening to and validating a patient’s complaints of shortness of breath, dizziness, or chest pain. In a setting like a waxing appointment, what’s more important than what the client is telling you?
• Alternative Assessment Tools: Using other objective measures when appropriate, such as arterial blood gas analysis, which provides a direct and accurate measurement of oxygen and carbon dioxide levels in the blood.

This is especially true for something like professional waxing. The goal is client comfort, so their direct feedback is what matters most. A client telling you they’re in pain is a more reliable indicator than any device could ever be.

3. Standardized Education and Training

This has to become a mandatory part of the curriculum in medical schools, nursing programs, and for continuing ed. Every provider needs to be trained on the specific limitations of pulse oximetry on darker skin. The training needs to cover:

• The physiological basis of melanin’s interference with pulse oximeters.
• Clinical signs of hypoxemia that may be present despite seemingly normal oximetry readings.
• Strategies for multimodal assessment and decision-making when discrepancies arise.
• The importance of cultural competence and acknowledging potential biases in medical technology and practice.

And this isn’t just for doctors and nurses. Aestheticians and other professionals who work with clients’ bodies need to know about these issues too. If you understand how different skin types react and know that some of our tools are biased, you can provide much better, safer, and more equitable comfort for everyone who walks in your door.

4. Advocacy and Policy Changes

Advocacy groups are on the front lines here, pushing regulators like the FDA to force manufacturers to test their devices on people with a wide range of skin tones before they get approved. The FDA is moving on this, but constant pressure from doctors, nurses, and the public is what will really speed things up. That means demanding specific things, like dedicated funding for research into equitable tech and clear guidelines that make inclusive testing non-negotiable.

What Success Looks Like: Real-World Improvements

Putting these fixes into practice will lead to real, measurable improvements in care, getting us closer to a system that actually provides inclusive pain assessment and equitable comfort. Here’s what we should expect to see:

• Reduced Diagnostic Delays: With better oximeters and smarter clinical work, we’ll catch hypoxemia sooner in patients with darker skin, which means getting them the treatment they need before things get worse.
• Improved Patient Outcomes: Better O2 monitoring means safer patients. It’s a direct line, more accuracy equals less harm and fewer deaths, particularly for patient populations let down by our tech. If a basic safety check works for one group but not another, you don’t have equity.
• Enhanced Trust in Healthcare: When patients see that their specific physiology is being considered, and they feel heard, they begin to trust the system more. That trust is critical, because without it, people are less likely to seek care or follow medical advice.
• More Inclusive Device Design: All this awareness and regulatory heat will force innovation. New medical devices will have to be designed with diversity included from the very beginning. This sets a new standard for the entire industry: prove your tech works for everyone, or don’t bother bringing it to market.
• Greater Health Equity: In the end, fixing the pulse oximeter is one concrete way to start chipping away at systemic health disparities. It’s an admission that a one-size-fits-all approach is a failed approach and that we have to do better.

We’re not there yet with device accuracy, but the next steps are clear. By admitting the problem, building better tools, and training practitioners to look beyond the numbers, we can make sure every patient gets the right assessment. This isn’t just about good practice. It’s about providing the same high standard of care to everyone, regardless of their skin tone.

Fixing something as basic as a pulse oximeter is how we make health equity real, ensuring our technology delivers equitable comfort and safety for all.