Oxygen Levels, Pulse Oximeters, and COVID-19
How does COVID-19 affect a person’s oxygen levels?
Many people with COVID-19 have low oxygen levels, even when they are feeling well. Low oxygen levels can be an early warning sign that people need medical care.
What is a pulse oximeter?
A pulse oximeter is a small device that clips onto your finger (or other body part) and measures the level of oxygen in your blood. They are used often in hospitals and clinics, and you can also buy them to use at home. Many consider oxygen level a vital sign, like blood pressure. If you have a lung or heart condition, you may use a pulse oximeter at home to monitor your condition, as directed by your health care provider. People can buy pulse oximeters without a prescription at some pharmacies and stores.
Should I use a pulse oximeter at home to know if I have COVID-19, or to monitor my COVID-19?
We do not recommend using a pulse oximeter to diagnose COVID-19 yourself. If you have symptoms or have been close to someone with COVID-19, get tested.
If you have COVID-19, a pulse oximeter might be a helpful tool for you to monitor your health and help know if you need medical care. While a pulse oximeter may help you feel some control over your health, it does not tell the whole story. Your oxygen level measured by a pulse oximeter is not the only way to know how sick you are. Some people may feel very sick and have good oxygen levels, and some may feel OK but have poor oxygen levels.
You might also have low oxygen levels if you feel short of breath, are breathing faster than usual, or feel too sick to do your usual daily activities. Call a health care provider right away if you have these symptoms.
What are normal readings, and when should I worry?
Your pulse oximeter will show you your oxygen level as “SpO2.” Normal oxygen levels are at least 95%. Some patients with chronic lung disease or sleep apnea can have normal levels around 90%.
If your home SpO2 reading is less than 95%, call your health care provider.