Respiratory acidosis is a condition that occurs when the lungs cannot remove all of the carbon dioxide the body produces. This disrupts the body's acid-base balance causing body fluids, especially the blood, to become too acidic.

Causes of respiratory acidosis include:

• Diseases of the airways (such as asthma and chronic obstructive lung disease), which send air into and out of the lungs
• Diseases of the chest (such as scoliosis), which make the lungs less efficient at filling and emptying
• Diseases affecting the nerves and muscles that "signal" the lungs to inflate or deflate
• Drugs that suppress breathing (including powerful pain medicines, such as narcotics, and "downers," such as benzodiazepines), especially when combined with alcohol
• Severe obesity, which restricts how much the lungs can expand

Chronic respiratory acidosis occurs over a long period of time. This leads to a stable situation, because the kidneys increase body chemicals, such as bicarbonate, that help restore the body's acid-base balance.

Acute respiratory acidosis is a severe condition in which carbon dioxide builds up very quickly and before the kidneys can return the body to a state of balance.