When your carbon dioxide (CO2) level is low in the blood, it generally means your body is removing too much CO2, which can disrupt your body's acid-base balance and pH. Low CO2, also called hypocapnia or hypocarbia, can lead to increased blood alkalinity—a condition known as respiratory alkalosis. This imbalance may affect enzyme function, oxygen delivery to tissues, and overall cellular processes. Common causes of low blood CO2 include:
- Respiratory causes: hyperventilation (rapid or shallow breathing often triggered by stress or anxiety), asthma, chronic obstructive pulmonary disease (COPD), altitude sickness, pulmonary embolism, pneumonia, and other lung conditions.
- Metabolic causes: metabolic acidosis (such as diabetic ketoacidosis), kidney disease, sepsis, salicylate (aspirin) overdose, Addison's disease, and lactic acidosis (from intense exercise or conditions like sepsis).
- Other factors: medication side effects, pregnancy, heatstroke, and certain endocrine disorders like hyperthyroidism.
Symptoms related to low CO2 can range from dizziness, lightheadedness, and shortness of breath to more severe issues such as confusion, muscle cramps, seizures, and headaches due to reduced blood flow to the brain. In essence, low carbon dioxide in the blood indicates an underlying physiological imbalance that may affect respiratory or metabolic functions and often requires medical evaluation to determine the precise cause and appropriate treatment. If you experience symptoms or have test results showing low CO2, consult a healthcare provider to explore the next steps.
