Respiratory alkalosis is a fall in blood carbon dioxide caused by breathing faster or deeper than the body requires. This raises blood pH and can produce neurological and muscular symptoms.

Causes

The National Library of Medicine lists anxiety, pain, fever, pregnancy, severe anaemia, liver disease and brain abnormalities among possible causes. Lung disease, pulmonary embolism, high altitude and some medicine overdoses can also trigger overbreathing.

Symptoms and testing

Dizziness, light-headedness, tingling, chest discomfort, breathlessness or confusion can occur. Clinicians may use an arterial blood gas, electrolyte tests, imaging or lung tests depending on the suspected cause.

Treatment

Treatment addresses the reason for hyperventilation. Anxiety is only one possibility and should not be assumed before serious causes are considered. Breathing into a paper bag can lower oxygen and is unsafe when the cause is uncertain; it should not be used without professional direction.

Sudden breathlessness, chest pain, fainting, confusion or possible overdose requires urgent care.