COVID-19 is a respiratory infection. It can cause difficulty breathing and can lead to low levels of oxygen in your bloodstream. Low levels of oxygen make it impossible for your body to function normally and can be life threatening.
Monitoring blood oxygen levels at home is one way to keep an eye on your COVID-19 infection and recovery. You can measure your blood oxygen levels with an inexpensive and easy-to-use device called a pulse oximeter.
A pulse oximeter gives you your blood oxygen level as a simple percentage. Any pulse oximeter reading of lower than 90 percent is a sign you need to seek urgent medical care.
Your blood oxygen level is a measure of the amount of oxygen in your blood.
Your body gets oxygen when you breathe in. As air passes through your lungs, oxygen moves into your bloodstream. When your lungs are inflamed due to a severe infection like COVID-19, you may take in less oxygen with each breath.
You need the right level of oxygen in your bloodstream for your body to perform essential functions, like keeping your heart beating. The oxygen in your blood also helps your cells create energy. That energy enables you to think, move, and carry out other daily tasks.
Blood oxygen levels are measured as a percentage. Levels that are closer to 100 percent are best and mean that your body has enough oxygen.
For most people, an oxygen level of 95 percent or higher is standard and healthy.
Some people with chronic lung conditions like chronic obstructive pulmonary disease (COPD) live with lower-than-average blood oxygen levels.
If you have a lung condition, you should call your doctor as soon as you test positive for COVID-19. Your doctor can advise you on how to monitor and treat your condition during the infection.
If you’re monitoring your blood oxygen at home with a pulse oximeter, follow these general guidelines:
- Contact a doctor if your blood oxygen level falls below 95 percent
- Seek emergency medical care if your blood oxygen level falls below 90 percent.
A pulse oximeter (pulse ox) is a device that can measure your blood oxygen level quickly and noninvasively. They’re regularly used in doctor’s offices and hospitals, so you’ve most likely had one clipped on your finger before.
During a respiratory illness like COVID-19, your doctor might recommend that you use a pulse oximeter at home to keep track of your blood oxygen levels.
Blood oxygen levels can sometimes drop dangerously low without causing symptoms like shortness of breath. In these instances, a pulse oximeter can help detect low oxygen levels early on, when they can be treated with supplemental oxygen.
Overall, pulse oximeters can be a helpful tool for people with COVID-19. You can buy a pulse oximeter at most drug and grocery stores without a prescription.
Pulse ox readings in people with darker skin
Pulse oximeter readings aren’t perfect. Readings can sometimes be inaccurate, especially in people with darker skin. Because they work by passing a beam of light through your finger, skin tone can affect the results.
Studies have found that in people who self-identify as Black, pulse ox readings are often several points higher than their true values, which can be measured with a blood test called an arterial blood gas.
One study found that Black people were more than three times more likely than white people to have a pulse oximetry reading higher than the true value.
To get more reliable data on blood oxygen levels in people with darker skin, it’s best to take regular readings throughout the day and to keep a record. That way, you’ll notice any downward trends.
Low blood oxygen can affect how your body functions. It can cause severe symptoms, but sometimes it causes no symptoms at all. Either way, it can be life threatening.
Symptoms of a low blood oxygen level include:
The primary treatment for low oxygen levels is oxygen therapy. Oxygen therapy gets oxygen into your bloodstream and helps take the pressure off your lungs so that you recover from COVID-19.
There are a few ways to receive oxygen therapy. In most cases, you’ll receive extra oxygen through a nasal cannula.
A nasal cannula is plastic tubing that sits in your nose. Oxygen from a tank goes into the tubing and then into your body. Doctors and respiratory therapists can adjust the amount of oxygen you receive until your blood oxygen levels return to normal.
As you start to recover, they can slowly reduce the amount of oxygen you receive through the tubing.
If you need more support, you might receive oxygen therapy through a process called intubation. This involves putting plastic tubing directly into your trachea, or windpipe.
Intubation helps keep your airways open so that oxygen can get to your body. The tubing can then be connected to an oxygen supply. As you recover, you’ll transition from intubation to a nasal cannula and tank oxygen.
In some cases, you might be discharged from the hospital with portable oxygen, home oxygen tanks, and a nasal cannula.
In other cases, your treatment team might want you to be breathing entirely on your own and achieving healthy blood oxygen levels before discharge. Your goals will depend on factors such as:
- your overall health
- your age
- any existing lung conditions
- whether COVID-19 has damaged your lungs
You can take steps at home to help keep your oxygen levels up.
Your treatment team might have given you specific instructions, especially if you were sent home with oxygen. It’s important to follow any instructions you were given by your doctor or respiratory therapist.
Steps you can take on your own include:
- Stop smoking, if you smoke. Smoking reduces the amount of oxygen circulating in your body.
- Adjust your sleeping position. It’s best to avoid sleeping flat on your back. Instead, try sleeping on your side. You can also sleep on your stomach with pillows propped under your neck, chest, thighs, and chin.
- Try pursed-lip breathing. Pursing your lips like you’re about to whistle and breathing deeply is a great way to reduce shortness of breath and increase blood oxygen levels.
- Adjust how you sit. Try sitting up straight with a pillow behind your back when you’re on a couch or chair to help your lungs get more oxygen.
- Get plenty of fresh air. Spend time outdoors or keep your windows open to ensure you’re getting fresh air.
- Go for a walk. Short walks can increase your circulation and blood oxygen level.
COVID-19 is a respiratory infection that can lead to dangerously low blood oxygen levels. This is a medical emergency that requires immediate care. A pulse oximeter can help you monitor your blood oxygen levels at home.
The best use of a pulse oximeter as an indicator of when to call a doctor or seek emergency care. For most people, any reading of lower than 95 percent is a sign to call a doctor.
However, it’s important for everyone to seek urgent care if their blood oxygen level drops below 90 percent.