MSD Manual

Please confirm that you are a health care professional

honeypot link

Hyperventilation Syndrome


Rebecca Dezube

, MD, MHS, Johns Hopkins University

Reviewed/Revised Nov 2023
Topic Resources

Hyperventilation syndrome is anxiety-related dyspnea and tachypnea often accompanied by systemic symptoms. It can be acute or chronic. Diagnosis is by exclusion. Treatment is supportive.

Hyperventilation syndrome most commonly occurs among young women but can affect either sex at any age. It is sometimes precipitated by emotionally stressful events. Hyperventilation syndrome is separate from panic disorder Panic Attacks and Panic Disorder A panic attack is the sudden onset of a discrete, brief period of intense discomfort, anxiety, or fear accompanied by somatic and/or cognitive symptoms. Panic disorder is the occurrence of repeated... read more , although the two conditions overlap; about half of patients with panic disorder have hyperventilation syndrome and one quarter to one half of patients with hyperventilation syndrome have panic disorder (1 Reference Hyperventilation syndrome is anxiety-related dyspnea and tachypnea often accompanied by systemic symptoms. It can be acute or chronic. Diagnosis is by exclusion. Treatment is supportive. Hyperventilation... read more ).


  • 1. Cowley DS, Roy-Byrne PP. Hyperventilation and panic disorder. Am J Med 1987;83(5):929-937. doi:10.1016/0002-9343(87)90654-1

Symptoms and Signs of Hyperventilation Syndrome

Patients with hyperventilation syndrome present with dyspnea sometimes so severe that they liken it to suffocation. It can be accompanied by agitation and a sense of terror or by symptoms of chest pain, paresthesias (peripheral and perioral), peripheral tetany (eg, stiffness of fingers or arms), and presyncope or syncope or sometimes by a combination of all of these findings. Tetany occurs because respiratory alkalosis Respiratory Alkalosis Respiratory alkalosis is a primary decrease in carbon dioxide partial pressure (Pco2) with or without compensatory decrease in bicarbonate (HCO3); pH may be high or near normal.... read more causes both hypophosphatemia Hypophosphatemia Hypophosphatemia is a serum phosphate concentration < 2.5 mg/dL (0.81 mmol/L). Causes include alcohol use disorder, burns, starvation, and diuretic use. Clinical features include muscle weakness... read more and hypocalcemia Hypocalcemia Hypocalcemia is a total serum calcium concentration < 8.8 mg/dL (< 2.20 mmol/L) in the presence of normal plasma protein concentrations or a serum ionized calcium concentration < 4... read more . On examination, patients may appear anxious, tachypneic, or both; lung examination is unremarkable.

Diagnosis of Hyperventilation Syndrome

  • Testing to exclude other diagnoses (chest x-ray, ECG, pulse oximetry)

Hyperventilation syndrome is a diagnosis of exclusion; the challenge is to use tests and resources judiciously to distinguish this syndrome from more serious diagnoses.

Basic testing includes

  • Pulse oximetry

  • Chest x-ray

  • ECG

Pulse oximetry in hyperventilation syndrome shows oxygen saturation at or close to 100%. Chest x-ray is normal. ECG is done to detect cardiac ischemia, although hyperventilation syndrome itself can cause ST-segment depressions, T-wave inversions, and prolonged QT intervals.

Occasionally, hyperventilation syndrome is indistinguishable from acute pulmonary embolism Pulmonary Embolism (PE) Pulmonary embolism (PE) is the occlusion of pulmonary arteries by thrombi that originate elsewhere, typically in the large veins of the legs or pelvis. Risk factors for pulmonary embolism are... read more Pulmonary Embolism (PE) , and tests for pulmonary embolism (eg, D-dimer, ventilation/perfusion scanning, CT angiography) may be necessary.

Treatment of Hyperventilation Syndrome

  • Supportive counseling

  • Sometimes psychiatric or psychologic treatment

Treatment is reassurance. Some physicians advocate teaching the patient maximal exhalation and diaphragmatic breathing. Most patients require treatment for underlying mood or anxiety disorders; such treatment includes cognitive therapy, stress reduction techniques, drugs (eg, anxiolytics, antidepressants, lithium), or a combination of these techniques.

NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
quiz link

Test your knowledge

Take a Quiz!