Chronic obstructive pulmonary disease (COPD) causes changes in your lungs that affect your breathing. As a result, you may not get enough oxygen or use it fully. That can lead to hypoxia, which is when cells or tissues in your body don’t get as much oxygen as they need.
What Causes Hypoxia
Damage from COPD sometimes keeps the tiny air sacs in your lungs, called alveoli, from getting enough oxygen. That's called alveolar hypoxia.
This kind of hypoxia can start a chain reaction that leads to low oxygen in your blood, or hypoxemia. Hypoxemia is a key reason for the shortness of breath you get with COPD.
In turn, hypoxemia can cause hypoxia in other parts of your body (tissue hypoxia). That happens when your blood doesn't carry enough oxygen to your tissues.
Tissue hypoxia can affect any cells that don’t get enough oxygen or use it properly. Your body may be able to adapt to mild or temporary hypoxia. But tissue hypoxia can become serious, even fatal.
Although COPD hypoxemia and hypoxia both stem from a lack of oxygen, you can have one without the other.
With either hypoxia or hypoxemia, you'll probably feel short of breath. You might cough and wheeze.
Early on, hypoxia can make you feel anxious, upset, and restless. You may look pale.
If it gets worse, you could pass out. Your skin and lips might look a little blue. Serious hypoxia can cause your heart and breathing to stop suddenly (cardiorespiratory arrest). It can also damage your brain and other organs within minutes.
With hypoxemia, your breathing and heart rates might go up. A small device called a pulse oximeter measures how much oxygen is in your blood. Normal levels are between 95% and 100%. A reading of 88% or below signals hypoxemia.
Get medical help right away if you notice signs of hypoxia.
The treatment for serious hypoxia or hypoxemia is extra oxygen. You may get it through a tube called a nasal cannula or a face mask.
You could need round-the-clock oxygen. But small amounts might be enough if you just get short of breath during exercise or have slightly low oxygen levels.
Your doctor may use a device called a high-flow nasal cannula. It gives you oxygen that's been heated and humidified (had moisture added). This can work better than traditional oxygen therapy.
You might have long-term oxygen therapy at home. You could be on oxygen for 18 hours a day.
Many of the serious problems COPD causes happen because your lungs and bloodstream get too little oxygen. If not treated, alveolar hypoxia and hypoxemia can lead to high blood pressure in your lungs (pulmonary hypertension) and raise your risk for heart problems.
Pulmonary hypertension is often mild. But it can get worse during a COPD flare-up. In rare cases, it leads to a type of heart failure called cor pulmonale. You might need long-term oxygen therapy if you’re at risk.
Widespread inflammation from hypoxia and hypoxemia can cause you to lose muscle and make your muscles get tired faster. It may also lead to thinking problems, like slower mental speed and inattention.
To help prevent these problems, follow your doctor's recommendations for COPD treatment and healthy lifestyle changes.