Chronic obstructive pulmonary disease, or COPD, is a name for several conditions that affect breathing, including chronic bronchitis and emphysema. Hypoxia is one of the harmful effects of COPD when not enough oxygen moves around the body, impacting organ function.
According to the Centers for Disease Control and Prevention (CDC), around 16 million people in the United States have COPD. Millions more people have undiagnosed COPD and are not receiving treatment.
In this article, we explain the effects of hypoxia due to COPD, what causes it, and how to treat the condition.
The lung damage that occurs with COPD can cause hypoxia if it becomes too severe.
COPD can have harmful effects on the body when it interferes with oxygen levels. If hypoxia progresses too far, it can lead to disability and death.
Oxygen passes into the blood from lung tissue through the alveoli, or air sacs. Oxygenated blood then leaves the lungs and travels around the body to other tissues. Vital organs and systems, especially the brain and heart, need enough oxygen to survive.
COPD damages the air sacs in the lungs and interferes with this process. If the damage reaches a critical point, a person may develop hypoxia. Hypoxia occurs when the blood does not deliver enough oxygen to the air sacs in the lungs.
A person’s body can adapt to cope with lower oxygen levels than are usual. However, in people with COPD, hypoxia in the lungs means oxygen levels become extremely low.
When oxygen levels reach so low a level, the organs in the body do not get enough oxygen and start to develop damage and injury. This is known as hypoxemia.
People with COPD-related hypoxia may experience the following symptoms:
- difficulties trying to catch their breath
- frequent coughing
- a choking sensation due to shortness of breath
- less ability to tolerate physical activity
- rapid breathing
- waking up in the night being unable to catch a breath
Hypoxia and hypoxemia can also lead to other conditions, including:
Hypoxia can cause injury to the brain and nerve cells. It may trigger changes in brain function and thought processes.
If COPD brings down brain oxygen levels too much, it can also reduce the number of neurotransmitters that the brain creates.
Neurotransmitters are chemical messengers that ensure different parts of the brain and nervous system can communicate with each other. Sufficient oxygen is essential for creating these neurotransmitters and making sure they function correctly.
Typically, the right side of the heart pumps low oxygen blood to the lungs. Once it reaches the lungs, blood can pick up oxygen from inhaled air. The oxygenated blood then returns to the left side of the heart, which pumps it throughout the body.
A person with COPD can experience inflammation in the arteries that transfer blood from the right side of the heart to the lungs. This inflammation can cause high pressure to develop in these arteries, which is also known as pulmonary hypertension.
This higher pressure means that the right side of the heart has to work harder to pump blood through those arteries. This can cause damage to the heart, making it weak.
Secondary polycythemia is the body’s response to chronic hypoxia due to COPD. The body starts creating extra red blood cells to transport more oxygen. Extra blood cells mean that the blood is more prone to clotting.
In people who have COPD, this condition can also increase the risk of abnormal heart rhythms, longer hospital stays, and more breathing complications.
Skeletal muscle dysfunction
People whose COPD has reached a more advanced stage can have difficulty engaging in physical exercise and activity. As a result, their muscles start to become weaker. The weakened muscles are more easily fatigued, making it even harder for a person with COPD to exercise.
A chronic lack of oxygen can cause inflammation in the body’s tissues, which can lead to several conditions.
The best treatments for COPD-related hypoxia and hypoxemia are those that keep the airways open and reduce inflammation. Preventing infections can also help, as some infections reduce lung function even further.
Examples of management for COPD hypoxia and hypoxemia include:
- Bronchodilator therapy: People typically inhale these medications from an inhaler or nebulizer. The drugs reduce spasms and tightness in the smooth muscle of the airways. This can help a person improve their oxygen flow.
- Immunizations: A person can get a regular flu shot and scheduled vaccines for pneumonia and pertussis, or whooping cough. These can help prevent infections that could make lung hypoxia and COPD worse.
- Oral or inhaled corticosteroids: These medications reduce inflammation in the airways and throughout the body during a COPD flare. Examples include beclomethasone and prednisone.
- Quitting smoking: If a person with COPD smokes, quitting smoking can have significant benefits in treating the condition and reducing the severity of symptoms. Quitting also boosts the immune system and helps it fight against potential infections.
- Pulmonary rehabilitation therapy: This treatment involves training an individual in the best ways to breathe when their lungs are impaired. It reduces the decline of lung function and increases a person’s ability to exercise.
Along with nutritional counseling, pulmonary rehabilitation therapy can help a person with COPD improve their breathing and oxygen levels around the body.
If a person has severe hypoxemia due to COPD, a doctor will commonly recommend oxygen therapy.
Oxygen therapy involves breathing in extra oxygen through a small, flexible tube, or nasal cannula, that fits in the nostrils.
According to a 2019 study in PLoS One, long-term oxygen therapy may improve the quality of life for people with COPD hypoxemia by decreasing COPD flares and increasing tolerance to physical activity.
Current studies show that individuals with severe COPD are likely to benefit the most from oxygen treatment.
However, not everyone with COPD is a good candidate for supplemental oxygen. It is essential that a doctor carefully prescribes and closely monitors oxygen therapy. Too much oxygen can lead to higher carbon dioxide levels.
Although exercise can be challenging for people with COPD, physical activity can improve oxygen uptake in the lungs of a person with mild COPD and improve their breathing patterns.
However, those with more advanced hypoxia may find any amount of physical activity difficult.
COPD is a progressive condition, which means it gets worse over time. The airflow difficulties of COPD are irreversible, even after treatment.
This is especially true if smoking was a key factor in a person developing COPD, and they continue to smoke.
Several key factors affect the outlook for a person with COPD, including:
- body mass index (BMI)
- how often they experience COPD flares
- level of breathlessness after physical activity
- degree of hypoxemia
- pulmonary artery pressures
- results of a pulmonary function test
- resting heart rate
- smoking status
- other health conditions unrelated to the lungs
While COPD is a progressive condition, some people have more stable COPD and can live for a long time with the condition.
The best outcomes are related to regular follow-up with doctors, closely following the prescribed course of medication, and living a healthful lifestyle.