The blood comprises red blood cells, white blood cells, platelets, and plasma. Plasma is the blood’s largest part, consisting of water, salt, enzymes, antibodies, and nutrients like glucose and cholesterol. It also contains carbon dioxide, a waste product created when your body metabolizes food for energy.
Usually, carbon dioxide levels in the plasma are closely linked with bicarbonate levels, another waste product produced by metabolism. That’s why when doctors talk about low CO2 levels, they’re talking about low bicarbonate levels. A normal HCO3- level is 22-26 mEq/L. Anything below that is considered low.
Two leading causes of low bicarbonate levels are respiratory acidosis and metabolic acidosis. Respiratory acidosis happens when there’s too much carbon dioxide in the blood because of poor ventilation or breathing difficulties. Metabolic acidosis occurs when there’s too much acid in the blood because of kidney problems or certain medications.
If doctors suspect low bicarbonate levels, they’ll order an arterial blood gas test to measure the blood’s pH level and concentrations of oxygen and carbon dioxide. The results will help doctors determine the cause of low bicarbonate levels and the best course of treatment.
Shortness of Breath
The air we breathe is a mixture of different gases. The main gas in the air you breathe is nitrogen, but oxygen is also present in significant amounts. Another gas that is present in small quantities is carbon dioxide. While carbon dioxide may not seem important, it plays a crucial role in the respiratory system.
When we breathe, oxygen enters the lungs and diffuses into the blood. At the same time, carbon dioxide leaves the blood and enters the lungs. This exchange of gases happens because blood is constantly trying to maintain a balance of oxygen and carbon dioxide. Therefore, shortness of breath can signal that something is wrong with the respiratory or circulatory system, especially if carbon dioxide levels are low.
In healthy adults, the level of carbon dioxide in their blood is usually around 40 mmHg. However, people with certain medical conditions may have lower carbon dioxide levels in their blood. For example, people with lung disease or heart failure may have blood levels as low as 30 mmHg. In these cases, shortness of breath signals something wrong with their respiratory or circulatory system.
