Hypercapnia is a medical condition characterized by an excess of carbon dioxide (CO2) in the bloodstream. This usually occurs when the body cannot effectively remove CO2 through breathing. Common causes include respiratory diseases, such as chronic obstructive pulmonary disease (COPD), or situations where breathing is impaired, like during sleep apnea. Symptoms of hypercapnia can include headaches, dizziness, confusion, and shortness of breath. If left untreated, it may lead to more severe complications, such as respiratory failure. Treatment often focuses on improving ventilation and addressing the underlying cause of the condition.