Blood gas

Blood gas refers to the gases that are dissolved in the blood. The term is most commonly used in relation to the measurement of these gases, which is an important part of medical practice. The primary blood gases are oxygen and carbon dioxide, but other gases such as nitrogen and carbon monoxide can also be present.

Overview

Blood gases are crucial for the functioning of the body. Oxygen is needed for cellular respiration, the process by which cells produce energy. Carbon dioxide is a waste product of this process, and must be removed from the body. The balance of these gases in the blood is therefore a key indicator of health.

Measurement

The measurement of blood gases is typically done through a blood gas test, also known as an arterial blood gas (ABG) test. This involves taking a blood sample from an artery, usually in the wrist. The sample is then analyzed in a laboratory to determine the levels of oxygen and carbon dioxide, as well as other parameters such as the blood's pH and the levels of bicarbonate, a substance that helps regulate pH.

Clinical significance

Abnormal blood gas levels can indicate a range of health problems. Low oxygen levels (hypoxia) can be a sign of conditions such as chronic obstructive pulmonary disease (COPD) or heart failure. High carbon dioxide levels (hypercapnia) can indicate problems with the respiratory system, such as asthma or sleep apnea. Blood gas tests are therefore an important tool in the diagnosis and management of these and other conditions.

See also

• Respiratory system
• Blood tests
• Acid-base imbalance