Author
Bowtie Team
Updated on
2025-06-10
Disclaimer: This article is translated with the assistance of AI.
With COVID cases rising in Hong Kong, many are turning to pulse oximeters to monitor blood oxygen levels and spot early signs. Bowtie breaks down the ins and outs of fingertip devices, proper usage tips, operating principles, key precautions, and what to do if your oxygen readings change. Stay informed!
What is Blood Oxygen?
Blood oxygen saturation, or SpO2, measures the percentage of oxygen in your blood, and it’s normally between 95-100% 1 . If it drops below that level, you might experience symptoms like shortness of breath, difficulty breathing, chest pain, or headaches 1 .
What is Silent Hypoxia? 2
Silent hypoxia refers to a situation where a person’s blood oxygen levels drop (as low as 50-80%), but they don’t show obvious signs like shortness of breath or rapid breathing . In silent hypoxia, the body’s organs can suffer indirect damage from the lack of oxygen and inflammation, particularly causing long-term harm to the brain and lungs. Since the symptoms aren’t always obvious, it can delay treatment and, in severe cases, even become life-threatening.
Who Needs to Monitor Blood Oxygen Levels?
People with the following conditions or situations 3 might need to regularly monitor their blood oxygen levels:
How Does Blood Oxygen Relate to the Coronavirus?
Some (but not all) COVID-19 patients may experience low blood oxygen levels 3 , however, blood oxygen levels are not a method to determine if a patient is diagnosed with COVID-19, as COVID-19 patients can also have normal blood oxygen levels; similarly, low blood oxygen levels do not necessarily mean the person is infected with the coronavirus 3 . Therefore, do not rely solely on blood oxygen measurement as a way to diagnose COVID-19 (it can be used as a supplementary method); the only reliable method is the specific virus test for COVID-19 3 .
How Pulse Oximeters Measure Blood Oxygen Levels
Consumer Council ‘s report on blood oxygen levels indicates that pulse oximeters are non-invasive devices that measure the oxygen saturation of hemoglobin in peripheral microvessels (SpO2), providing blood oxygen level readings 4 . Pulse oximeters emit signals in specific wavelengths and are highly sensitive to areas with dense microvessels, such as fingertips or toes 4 .
Since hemoglobin in red blood cells exhibits different light absorption properties for red light and near-infrared light depending on the oxygen level, pulse oximeters use photoelectric sensors to measure the red light and near-infrared light that passes through or reflects from the detection area, thereby calculating the oxygen saturation (SpO2) level 4 .
What’s the Difference Between Hospital and Home Pulse Oximeters? 4
Hospital and home pulse oximeters work on the same principle, but hospital ones are generally larger, don’t always need to clip onto a finger, and can be applied as adhesive patches on the finger or forehead for better comfort. Plus, they’re clinically tested, so they’re more accurate and pricier.
Home finger-style pulse oximeters are typically portable, smaller, and more affordable, but since they’re not clinically tested, their readings are just for reference. If you’re using one for ongoing monitoring, it might involve keeping it on your finger for extended periods, which could affect blood circulation in that area.
What Factors Affect the Accuracy of Pulse Oximeters? 5
The following factors can affect the accuracy of pulse oximeters, including:
- Darker skin tones or skin pigmentation
- The person being tested is moving or being moved
- Nail polish or artificial nails
- Low blood pressure (generally, systolic pressure needs to be above 80)
- Heart rate that’s too fast or too slow
- Intravenous dye injections
What Does Blood Oxygen Level Indicate?
What Actions Should Be Taken for Different Blood Oxygen Levels? 6
| Blood Oxygen Level | Recommended Actions |
| 95%–100% | Normal level; you can walk for 2 minutes and recheck |
| 91%–94% | Low blood oxygen level, which may indicate certain health risks; consider seeking medical advice |
| 90% or below | Concerning blood oxygen level, which may indicate serious health risks,
You are advised to call an ambulance immediately or head to the nearest emergency room for prompt X-rays and heart checks |
Home Pulse Oximeter Price Comparison
If you’re shopping for a home pulse oximeter, you’ll find they’re much more affordable than the ones used in hospitals, with plenty of options to choose from, typically costing just a few hundred dollars. The table below offers a handy comparison of prices for various home pulse oximeters to help you make an informed decision.
| Pulse Oximeter | Price $ |
| ChoiceMMed Fingertip Pulse Oximeter | $380 |
| Accumed Fingertip Pulse Oximeter | $199-299 |
| iHealth Smart Bluetooth Pulse Oximeter | $620 |
| Ionizo Fingertip Pulse Oximeter | $97-178 |
| Beurer Fingertip Pulse Oximeter PO30 | $500-698 |
| Heal Force Fingertip Pulse Oximeter A3 | $250-298 |
| Contec Pulse Oximeter CMS50M | $180-199 |
| Micro Sun Pulse Oximeter | $799-860 |
| Heal Force Prince-100N Fingertip Pulse Oximeter | $489 |
| Oxitech Pulse Oximeter | $399 |
| Rossmax SB220 | $399 |
How to Use a Pulse Oximeter to Monitor Blood Oxygen Levels?
Properly using a pulse oximeter helps monitor the oxygen level in your blood, effectively reminding patients to seek medical help early and avoid serious complications. Generally, people can monitor their blood oxygen levels twice a day, in the morning and evening, or more frequently as guided by healthcare professionals 6 .
What Should You Pay Attention To? 6
Before using the pulse oximeter, ensure that the device has batteries installed correctly. Turn on the oximeter and place your index finger inside the clip (with the fingernail facing up), then wait patiently for the reading to display. If no reading appears after a while, try using another finger and check if your finger is too cold or moist, if you have nail polish on, or if the surrounding environment is too bright, as these can affect the device’s operation.
The oximeter’s screen will display two sets of numbers: the SpO2 reading represents the blood oxygen concentration, and the other number is the heart rate.
Does Bowtie Insurance Provide Coverage for Abnormal Blood Oxygen Levels?
Patients with sleep apnea, chronic obstructive pulmonary disease, asthma, pneumonia 3 , and other conditions need to monitor their blood oxygen levels, Bowtie Term CI can provide financial assistance during the policyholder’s period of incapacity due to a critical illness, get a quote right away:
Bowtie Pink VHIS can provide actual cost coverage for medical expenses, with eligible expenditures fully reimbursed—check out the premium estimates now!
- * Bowtie Pink VHIS series fully reimburses eligible medical expenses for diagnosis, hospitalization, surgery, and specified non-surgical cancer treatments (excluding the US), subject to annual and lifetime coverage limits. Compensation amounts may be adjusted if the claim involves hospitals in mainland China outside the designated list, high-end hospitals within the designated list in mainland China, rooms exceeding the specified ward level, or pre-existing conditions.
FAQs About Blood Oxygen
How to Clean a Pulse Oximeter?
After purchasing a pulse oximeter, read the instructions carefully and clean the device as directed by the manufacturer, generally using a slightly damp cloth 4 . Since many parts are made of silicone, avoid cleaning with alcohol or organic solvents, and never submerge the entire device in water, as this could damage the circuitry and potentially cause electrical leaks 4 .
Can Children Use Fingertip Pulse Oximeters?
As long as you select the appropriate size and age-suitable model, children can use fingertip pulse oximeters 4 , but be sure to check that it fits securely on the finger to avoid inaccurate readings 4 .
Sources
- 1 Holland, Kimberly. “Blood Oxygen Levels: What Is a Normal Level?” Healthline, 25 Jan. 2017
- 2 Rahman, Ahsab, et al. “Silent Hypoxia in COVID-19: Pathomechanism and Possible Management Strategy.” Molecular Biology Reports, vol. 48, no. 4, 23 Apr. 2021, pp. 1–7
- 3 Cleveland Clinic. “Blood Oxygen Level: What It Is & How to Increase It.” Cleveland Clinic, 18 Feb. 2022
- 4 “Know More About Fingertip Pulse Oximeters | Demystifying the Mystery of Reading Deviations | Consumer Council.” Consumer.org.hk, 2024
- 5 Factors Affecting Pulse Oximeter Readings | Public Safety Training Facility | Monroe Community College.
- 6 “COVID-19: How to Monitor Your Blood Oxygen Level | New York City Department of Health.”
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