Breathlessness vs. Oxygen Saturation With COPD: Understanding the Difference
Shortness of breath, or feeling breathless, is what most people think of as the hallmark symptom of COPD. It's certainly one of the most common symptoms, as well as perhaps the scariest. This is true whether you're the person with COPD or the caregiver.1
But pulse oximeters, which measure your oxygen saturation levels, have become more popular and accessible over the past decade. Because of that, people with COPD may be relying as much on their oximetry results as their actual symptoms when evaluating their breathing status. And that can cause confusion.
The reason is that you can have "normal" oxygen saturation levels while feeling extremely short of breath. On the other hand, you may not notice any symptoms at all when your oxygen saturation levels dip dangerously low. How is this possible? That's what I hope to clarify in this post.
Short of breath vs. hypoxic
When you breathe, your lungs bring oxygen into your bloodstream, and your heart pumps it to your muscles and organs. This oxygen is then used to create energy for everything your body does, from walking to thinking.2,3
Many disease processes, such as COPD or heart disease, can affect this process. Medication, supplemental oxygen, and exercise may result in some improvements.
Feeling breathless
Being short of breath, or breathless, can result from several factors. Yes, this is a frequent symptom of COPD. But not everyone who feels short of breath has COPD. Besides lung damage or airway inflammation (such as with asthma), here are a few other factors to be aware of:1,4
- Heart health
- How fit you are
- Emotions
- Weather
- Altitude
- Infection
- Low red blood cell count (anemia)
It's important to understand, though, that feeling breathless does not always mean that you are hypoxic.
Being hypoxic or having hypoxemia
Hypoxemia means there is a low level of oxygen in the blood. Being hypoxic means that not enough oxygen is getting to your body's cells. You can test for these conditions by measuring your oxygen saturation level. There are 2 ways to measure it:2,3
- A blood test called arterial blood gases, done by your doctor or a lab tech
- A small hand-held device called a pulse oximeter that fits over a fingertip (it uses infrared rays to measure the percentage of oxygen in your blood)
Oxygen saturation depends on your overall health, how fast you are breathing, and your activity. Healthy people generally have oxygen saturation levels that range from 95 to 100 percent. Anything under 90 percent is considered low and unhealthy. It's not unusual for people who have COPD to dip below 90 percent at times.2,3
Short of breath, but not hypoxic
How is this possible? I've often seen this question, or related comment, in our community, "How can I be so short of breath, while my oxygen levels are still normal?" Understanding the answer to that is essential in knowing how to proceed. Even if you're extremely breathless, but your oxygen saturation levels remain in a healthy range, then supplemental oxygen may not be the answer.
Instead, it's important to know how to recover from breathlessness. Here are some steps that have worked for me:2
- Rest. Stop what you are doing and rest. This is the first thing you should do to get your breathing under control.
- Position yourself to breathe easier. Leaning forward or bending over helps create space for your diaphragm, making breathing easier. Lean your arms on your knees or an object like a wall or a counter. (I remember often seeing my dad doing this, especially after a severe coughing spell.)
- Work on controlling your breathing. If you know how to do diaphragmatic or pursed lip breathing, then do so. If you haven't learned those techniques yet, then at least work on slowing and deepening your breaths in and out.
Once you are feeling better and more in control of your breaths, it may be time to resume whatever you have been doing. But you may need to modify the intensity to avoid re-triggering your breathlessness.
Pulmonary rehab can help teach you how to avoid and/or deal with this symptom. In addition, a rescue, or quick-relief, inhaler is sometimes helpful. Talk with your doctor about these options, if you haven't already.
Hypoxic, but not short of breath
It might be hard to understand how your oxygen could be low if you are not feeling at all breathless. But here's the deal – having a low oxygen saturation level is not healthy! And it should not be ignored. Whether your low oxygen levels are measured by a blood test done by a health professional or by a pulse oximeter, pay attention.4
Even an oxygen level just slightly lower than 90 percent can be serious. It means your blood and tissues are not getting the oxygen they need to survive, and it needs to be addressed right away.3,4
The answer to hypoxia is supplemental oxygen. How much and how often you need it is a decision to be made in concert with your healthcare team. They can also help you with a plan for how often to measure your oxygen levels with a home pulse oximeter.3
Finding the best plan for you
When you have COPD, shortness of breath (and other symptoms, such as coughing) are an important measure of your current health status. However, knowing your saturation level is also important. And, unfortunately, it is entirely possible to be short of breath, but have healthy oxygen saturation. It is also possible to have unhealthy oxygen saturation levels, without any noticeable symptoms, at least initially.
So, taking a two-pronged approach to understanding your current respiratory status can be helpful. Talk with your doctor to come up with the best plan for you.
Join the conversation