Need Help? (888) GET LABS

High CO2 Levels in Blood: Meaning, Causes, and Treatment

Medically Approved by Dr. Edward Salko

Table of Contents

Disclaimer: The information in this article is not intended to replace professional medical advice, diagnosis, or treatment. Instead, consult your physician or any licensed healthcare providers if you have questions about thyroid disorders.

Table of Contents

What High CO2 Levels in the Blood Indicate

What Causes CO2 Levels to Rise?

Treatment for Elevated CO2 Levels

How to Prevent Increased CO2 Levels in the Blood

Frequently Asked Questions

The Bottom Line

High carbon dioxide (CO2) levels in your blood can wear you out when you consider the fact that it can alter your blood’s pH balance and electrolyte levels. What’s causing it, however, will depend on factors such as any underlying respiratory and non-respiratory health conditions. Learn more about what it means to have an elevated CO2 blood level, its treatment, and prevention below. 

What High CO2 Levels in the Blood Indicate

Suppose you have increased CO2 levels in your blood (clinically known as hypercapnia or hypercarbia). In that case, it means that your body is not removing the by-product properly, either due to a respiratory problem or another health issue that impedes the collection and excretion of CO2 to the lung. 

Carbon dioxide is a waste product generated during cellular respiration when your cells metabolize glucose or other macronutrient to be converted to energy. It is then collected by the red blood cells and brought to the lungs to be exhaled out of the body. If any of the steps or organs involved in the process is damaged or dysfunctional, it can lead to high CO2 levels in the blood. 

A buildup of CO2 causes the blood to become acidic. As a result, your kidney will have to work twice as hard to correct the electrolyte and blood pH balance by reabsorbing the bicarbonate. However, if this happens too frequently, the kidneys can become overwhelmed and can develop added health problems.  

Symptoms of High Levels of CO2 in the Blood

Recognizing the symptoms of hypercapnia is vital to understanding the underlying medical condition that caused the imbalance. These symptoms can vary based on how severe the CO2 elevation is in the blood. Still, the following are the most common symptoms to watch out for.

  • Shortness of breath
  • Tightness in the chest
  • Mental fog or confusion
  • Increased respiratory rate
  • Reddened skin 
  • Fatigue 
  • Headaches 

Keep in mind that these symptoms can also be found in other conditions. In the same way, you may have elevated carbon dioxide without manifesting all these. Hence, it’s still best to consult your primary care provider and undergo proper testing. 

Diagnosing High CO2 Blood Levels

A carbon dioxide blood test is typically requested to measure the level of CO2 in the blood. This involves taking your blood sample and having it analyzed in a laboratory to check if your CO2 level exceeds the healthy range. 

Generally, the normal carbon dioxide levels fall between 20 to 29 mmol/L. However, the reference value may vary slightly based on the testing protocol and the laboratory handling the analysis. 

Other tests that may back up the CO2 blood test include the electrolyte blood test panel and other specific lab workups your doctor may deem necessary based on the initial assessment. 

What Causes CO2 Levels to Rise?

High CO2 levels in the blood can be linked to several health conditions, such as COPD, kidney disease, Cushing syndrome, and cardiovascular disorder. These health issues directly impact the collection and removal of CO2 in the body. 

Since elevated CO2 concentration can occur from varied diseases, it’s important to consult a healthcare provider and undergo proper testing. Keep in mind that high CO2 in the blood is not a standalone or isolated symptom. Therefore, a professional assessment is the best way to address the health issue. 

Nevertheless, it helps to understand how some respiratory and non-respiratory diseases lead to increased CO2 levels. That said, read on to learn more.

Respiratory Health Issues

Given that carbon dioxide is removed from the blood and exhaled via the lungs and respiratory tract, it’s easy to associate respiratory dysfunctions with high CO2 levels. 

For example, if the lungs work below 100% capacity, they won’t likely collect enough CO2 in the blood to keep the concentration in a healthy range. The following are common respiratory disorders that may cause high CO2 levels in the blood. 

Chronic Obstructive Pulmonary Disease (COPD)

COPD is a collective respiratory disease characterized by an obstructed airway. It’s an umbrella term for medical conditions rooted in lung inflammation and/or tissue damage that make it hard to breathe. Two of the most recognized diseases under COPD are emphysema and bronchitis. 

Because airflow is restricted, the excretion of carbon dioxide from the lungs gets highly affected, making it much slower and less efficient. As a result, CO2 levels in the blood increase.   

Did You Know? According to the Centers for Disease Control and Prevention (CDC), cigarette smoking remains the top risk factor for developing COPD. Thus, if you’re a smoker, the first thing you should consider to have normal carbon dioxide levels is to withdraw from smoking.


A person who has asthma experiences inflammation in the airways. As a result, they have a higher risk of developing hypercapnia. In severe cases, CO2 levels can be extremely high, which may lead to respiratory failure. 

Non-respiratory Health Issues

Other medical conditions outside the respiratory system can also cause hypercapnia. Some of them directly cause the increased CO2 and even vice versa. These health issues include kidney failure, heart disease, and Cushing syndrome. 

Treatment for Elevated CO2 Levels 

To lower your CO2 levels, your doctor will prepare a treatment plan coupled with recommended  adjustments in your lifestyle. These may include the following:

  1. Changes in lifestyle 

Changing certain aspects of your lifestyle can reduce CO2 levels in your body. For example, if you smoke, the first step you need to take is to stop. Smoking damages the lungs and affects their ability to remove CO2.

In addition, exercising regularly is crucial to maintaining respiratory health and eliminating CO2.

Taking part in activities such as walking, jogging, or swimming can improve lung capacity and strengthen respiratory muscles. Furthermore, a healthy weight and a balanced diet can enhance respiratory health.

  1. Taking prescribed medications for CO2 reduction

Your doctor may prescribe certain medications to control elevated CO2 levels. For example, bronchodilators, such as inhalers, can help open up the airways and improve breathing. Often, these medications are prescribed for conditions like asthma or COPD, in which airway obstruction contributes to elevated CO2 levels.

Diuretics and corticosteroids can also be prescribed to address underlying conditions or reduce fluid retention, which can affect respiratory function. Still, which medication you need to take should solely depend on the recommendation and prescription of your healthcare provider. Hence, make sure you consult your doctor all the time. 

  1. Oxygen therapy (for severe cases)

Extremely high CO2 levels may require oxygen therapy. Oxygen therapy involves administering supplemental oxygen to improve blood oxygen levels. This can relieve symptoms such as shortness of breath and improve respiratory functions. Depending on the severity of the condition, oxygen therapy may be administered through nasal cannulas, oxygen masks, or other devices.

  1. Medical interventions for underlying conditions

In the case of elevated CO2 levels caused by underlying medical conditions, such as COPD or congestive heart failure, treating the underlying disease should help lower the high CO2 levels. Additional medical interventions, such as surgery, may be necessary to address respiratory issues or cardiac problems. Based on your specific needs and underlying conditions, your healthcare provider will develop a customized treatment plan.

How to Prevent Increased CO2 Levels in the Blood

Frequently Asked Questions

How are blood CO2 levels and blood pH related?

When carbon dioxide concentration increases in the bloodstream, it also elevates the levels of hydrogen ions. This decreases the pH level in the blood, making it acidic. On the other hand, if CO2 levels are low, the reaction becomes the reverse as the pH level increases, making your blood more basic. 

Is carbon dioxide life-threatening?

A mild increase in CO2 levels typically does not trigger any fatal complication, especially if the underlying cause is addressed. However, if the CO2 concentrations are extremely high, it can be toxic and life-threatening. You may experience rapid heartbeat and breathing, high blood pressure, mental fog, and other conditions mimicking suffocation.

How can I lower my CO2 levels naturally?

Aside from CO2-lowering medications, you can reduce carbon dioxide levels if you improve your respiratory capacity and strengthen your lungs. This includes quitting smoking the right way, getting enough exercise, doing proper breathing, and taking note of symptoms associated with lung problems.   

The Bottom Line

Understanding what it means to have high CO2 levels, it’s possible causes, and potential treatment can provide clarity on how the condition developed. But while the information above is helpful, your best chance of addressing hypercapnia is to work closely with your physician. Keep in mind that increased CO2 concentration in the blood is often a symptom of another underlying condition. Hence, you’ll need a more tailored medical intervention provided by a professional healthcare provider.

Share this article


Save up to
80% on meds!

We now offer pharmacy discounts through our PersonalabsRx platform.

We now offer pharmacy discounts through our PersonalabsRx platform.

Would you like to sign up for PersonalabsRx?