The key difference between hypoxia and hypercapnia is that hypoxia is a condition that is due to abnormally low levels of oxygen in the body tissues, while hypercapnia is a condition due to abnormally high levels of carbon dioxide in the blood.
Hypoxia and hypercapnia are two different types of key gas exchange abnormalities associated with respiratory diseases. Hypoxia is caused by hypoventilation, whereas hypercapnia is caused by chronic obstructive pulmonary disease (COPD) and sleep apnea. Both are critical life-threatening conditions that have to be treated immediately.
CONTENTS
1. Overview and Key Difference
2. What is Hypoxia
3. What is Hypercapnia (or Hypercarbia)
4. Similarities – Hypoxia and Hypercapnia
5. Hypoxia vs. Hypercapnia in Tabular Form
6. Summary – Hypoxia vs. Hypercapnia
What is Hypoxia?
Hypoxia is the abnormally low level of oxygen in the body tissues. Both lung disease and heart disease increase the risk of hypoxia. Someone who has hypoxia is called a hypoxic person. Hypoxemia is a related term to hypoxia, but it indicates low oxygen levels in the blood. Some features of hypoxia may include restlessness, headache, confusion, anxiety, tachycardia, tachypnea, difficulty breathing or shortness of breath, bradycardia, extreme restlessness, and bluish skin. Hypoxia is caused by underlying illnesses that affect blood flow and breathing, such as anemia, asthma, bronchitis, chronic obstructive pulmonary disease, congenital heart defect, congestive heart failure, emphysema, pneumonia, pneumothorax, pulmonary edema, pulmonary embolism, pulmonary hypertension, pulmonary fibrosis, and sleep apnea.
Figure 01: Hypoxia
Hypoxia can be diagnosed by performing pulse oximetry, arterial blood gas test (ABG), pulmonary function test (PFT), imaging tests like X-rays, CT scans, V/Q scans, and six-minute walk test (6MWT). Furthermore, hypoxia is treated through inhaled steroids, medications like diuretics, continuous positive airway pressure masks (CPAP), BiLevel positive airway pressure, supplemental oxygen, and mechanical ventilation in a hospital.
What is Hypercapnia?
Hypercapnia is also known as hypercarbia. It is due to high levels of carbon dioxide in the blood. Hypercapnia can be caused by chronic obstructive pulmonary disease (COPD), sleep apnea, conditions such as stroke, obesity, hypoventilation, etc., which reduce the ability to properly regulate breathing, conditions that affect the spinal cord, nerves, or controlling muscles such as multiple sclerosis (MS), differences in chest anatomy such as flail chest, toxins or poisoning (tetanus and botulism), pulmonary embolism, and vascular disease. Moreover, the features of hypercapnia may include shortness of breath, headaches, persistent tiredness, disorientation, confusion, paranoia, depression, and seizures.
Figure 02: Hypercapnia
Hypercapnia can be diagnosed through physical examination, pulse oximetry, arterial blood gas test, blood test (CO2 blood test), imaging tests such as chest X-rays or CT scans, and pulmonary function tests. Furthermore, hypercapnia is treated through non-invasive ventilation, oxygen therapy, medication such as opioids, and mechanical ventilation.
What are the Similarities Between Hypoxia and Hypercapnia?
- Hypoxia and hypercapnia are two different types of key gas exchange abnormalities.
- Underlying illnesses can cause both conditions.
- They may cause similar symptoms, such as shortness of breath, tiredness, headaches, etc.
- Both conditions can be diagnosed through physical examination and imaging tests.
- They are treated through ventilation
What is the Difference Between Hypoxia and Hypercapnia?
Hypoxia is a condition that is due to low levels of oxygen in the body tissues, while hypercapnia is a condition due to abnormally high levels of carbon dioxide in the blood. Thus, this is the key difference between hypoxia and hypercapnia. Furthermore, complications for hypoxia may include brain injury and cardiac arrest, while complications for hypercapnia may include respiratory acidosis, respiratory failure, cardiac arrest, and coma.
The infographic below presents the differences between hypoxia and hypercapnia in tabular form for side-by-side comparison.
Summary – Hypoxia vs Hypercapnia
Gas exchange is a physical process that happens in the lungs, between the alveoli and capillaries. During the gas exchange, oxygen moves from the lungs to the bloodstream. On the other hand, carbon dioxide passes from the blood to the lungs. Hypoxia and hypercapnia are two different types of gas exchange abnormalities. Hypoxia is the abnormally low level of oxygen in the body tissues, while hypercapnia is the abnormally high level of carbon dioxide in the blood. So, this summarizes the difference between hypoxia and hypercapnia.
Reference:
1. “Hypoxia (Medical).” Wikipedia. Wikipedia Foundation.
2. “Hypercapnia.” Cleveland Clinic.
Image Courtesy:
1. “Illustrations – Hypoxia” By Mayo Clinic (CC BY-NC-ND 2.0) via Flickr
2. “2325 Carbon Dioxide Transport” By OpenStax College – Anatomy & Physiology, Connexions Web site, Jun 19, 2013. (CC BY 3.0) via Commons Wikimedia