High Levels of Carbon Dioxide In the Blood

By Ashley | January 28, 2010

Carbon dioxide (CO2) is released by the body as a waste product, but it plays an important role in our body. Carbon dioxide helps in respiration by transportation of oxygen into the body cells. Apart from respiration, carbon dioxide is important for the normal functioning of the circulatory system, cardiovascular system, digestive system, and the maintenance of pH levels in the body. Carbon dioxide helps in dilation of soft tissues and thus helps protect muscles from spasms.

Pulmonary circulation transports deoxygenated blood away from the heart and brings back oxygenated blood to it. The amount of carbon dioxide going out from the body is replaced by the same amount of oxygen entering into the body through the lungs. Both high and low levels of carbon dioxide have negative impacts on the body. Carbon dioxide maintains the acid/alkaline level of the body by converting into carbonic acid. Low levels of carbon dioxide make the blood alkaline, thereby weakening the immune system. On the other hand, high carbon dioxide levels cause respiratory acidosis.

The carbon dioxide level in the blood has a direct impact on the production of gastric juices. Low carbon dioxide levels lead to less gastric juice production, resulting in ulcers. In cases wherein the carbon dioxide levels are high, various abnormalities result. The normal carbon dioxide level in the blood is 40 mm/Hg. When the level of carbon dioxide in the body is high, it is termed as hypercapnia. In this case, the carbon dioxide level in the body goes beyond 45 mm/Hg. High carbon dioxide levels or hypercapnia can be caused by the following factors:

  • Hypoventilation. When there is impaired gas exchange, the retention of carbon dioxide in the blood increases.
  • Respiratory failure. This occurs due to any lung infection, weakening of the lung muscle, sleep disorders, and diseases such as pulmonary embolism.
  • Inhalation of excess amount of carbon dioxide due to its high concentration in the air.

High Levels

Symptoms of high carbon dioxide levels in the blood are as follows:

  • Lethargy
  • Headaches
  • Skin blushing/flushing (skin become blue at some parts of body)
  • Tachycardia or increased heart rate
  • Short or vigorous breathing
  • Increased blood pressure
  • Involuntary muscle contraction

A test called ABG (arterial blood gas) has been prescribed by the physicians to check the levels of carbon dioxide and oxygen in the blood. ABG test also checks the lung activity based on the amount of oxygen inhaled and the amount of carbon dioxide exhaled from the lungs as well as the blood pH level. Arterial blood is preferable for the test because the blood flows to the tissues and cells through the artery. The exact amount of carbon dioxide and oxygen can be detected with the help of a blood gas analyzer.