HCO3 vs CO2
Carbon dioxide (CO2) comes in a form of gas and is a waste product resulting from the body’s metabolism. The blood transports carbon dioxide to the lungs where it will be exhaled. More than 90 percent of CO2 in the human blood is available as the bicarbonate (HCO3) form. The remaining carbon dioxide is either the dissolved form of the gas (CO2) or in carbonic acid form. The kidneys play an important role in maintaining the balance of bicarbonate, carbonic acid, and carbon dioxide in the blood.
Carbon dioxide is an important component of human blood. It is a product of cellular metabolism that is excreted via the lungs at the same moment when oxygen is taken in. This waste product takes part in the transport of oxygen from the blood to different body cells. CO2 is helpful in dilating the smooth muscle tissues, and it regulates the cardiovascular system. CO2 is converted into carbonic acid which becomes the prime regulator of the acid/base balance in the body. It also helps the digestive system function properly. Thus, carbon dioxide is an important component in the body, and its normal concentration in the blood should be 40mmHg.
When there is a disruption of the CO2 balance in the blood, certain conditions may result. When the CO2 levels in the blood exceed 45mmHg, the condition called hypercapnia results. The increase may be attributed to different factors such as drug overdosing, hypoventilation, diminished consciousness, lung diseases, seizures, and asthma.
Hypoventilation results when there is inadequate ventilation to carry out the necessary exchange of gases. When there is inadequate ventilation, the CO2 levels in the blood increase. While most people believe that oxygen is highly useful and CO2 is merely a waste product, the latter is needed by the body as well. When the balance of CO2 levels is disrupted, the respiratory pattern can also be disturbed. When CO2 levels, on the other hand, are reduced, the condition that results is called hypocapnia and is the opposite of hypercapnia. This condition may sometimes result from hyperkalemia and hypertension or high blood pressure. Hypocapnia is also a self-induced condition from hyperventilating.
Bicarbonate is another component in the blood which acts as a chemical buffer that maintains the pH balance of the blood. Bicarbonate reacts with hydrogen ions and result in the formation of carbonic acid which combines with water to bring carbon dioxide and extra water. The testing of bicarbonate is not done by itself, rather, a sample of the blood will be tested for other electrolytes such as chloride, potassium, and sodium.
When there is a high level of bicarbonate in the blood, it indicates that the body is having a problem keeping the acid-base balance or the electrolyte balance has been disturbed, perhaps from fluid loss or fluid retention. These imbalances can be caused by various dysfunctions.
The decrease in bicarbonate levels may be due to several causes which include:
- Chronic diarrhea
- Kidney disease
- Diabetic ketoacidosis
- Addison’s disease
- Metabolic acidosis
- Methanol poisoning
- Overdosing with salicylates
Bicarbonate levels are also increased by different medical conditions including:
- Severe vomiting
- Cushing’s syndrome
- Metabolic alkalosis
- Conn’s syndrome
- Lung disease, which also includes COPD
Summary:
- Both carbon dioxide and bicarbonate are present in the blood and are used to measure how well your lungs are working and how balanced is the acid-base component in the blood of people who are suffering from kidney diseases, heart problems, or diabetes.
- High levels of carbon dioxide result in hypercapnia while low levels result in hypocapnia.
- Bicarbonate is a chemical that maintains the acidity or alkalinity of the blood.