Hyperventilation syndrome

Hyperventilation Syndrome (Hyperventilation syndrome)

Disease Description (Causes and Symptoms)

• Definition: A condition in which excessive breathing lowers the level of carbon dioxide in the blood (PaCO2), causing respiratory alkalosis and various physical symptoms.
• Main pathophysiology:
  • Decreased PaCO2 → blood alkalinization → decreased ionized calcium (low ionized calcium) → peripheral nerve hyperexcitability (tingling, spasms, etc.).
  • Vasoconstriction (especially of the cerebral blood vessels) may cause dizziness, visual disturbances, and fainting.
• Common causes/triggers:
  • Mental stress, panic or anxiety attacks (major causes)
  • Infection (fever or sepsis), hypoxia, compensatory breathing due to metabolic acidosis, pulmonary or cardiac disease (such as asthma or pulmonary embolism), and certain medications
• Main symptoms:
  • Shortness of breath (rapid, shallow breathing), palpitations or chest tightness, dizziness or visual disturbances, tingling or numbness in the hands and feet, muscle spasms or tremors, fainting, abdominal bloating or abdominal pain, and possible arrhythmia
• Epidemiology: Relatively common in young women.

Treatment Methods

• Acute-phase treatment (during an attack)
  • Stabilization and reassurance: Relieving anxiety and creating a calm environment are priorities.
  • Breathing-control training (recommended): Slow, deep diaphragmatic breathing (inhaling through the nose and slowly exhaling through the mouth), guiding the patient toward gentle breathing at approximately 6–8 breaths per minute.
  • Rebreathing method (using a bag): Traditionally used to increase PaCO2 by having the patient rebreathe their own exhaled air. However, it is contraindicated when hypoxia or pulmonary or cardiac disease is suspected, or when oxygen saturation is low, so it should be used cautiously under the direction of emergency medical personnel.
  • Medication: If severe anxiety or panic is present, a single short-term dose of a benzodiazepine may be administered (at the physician’s discretion).
  • Oxygen: Used only when oxygen saturation is low or underlying pulmonary or cardiac disease is suspected.
• Treatment of the cause
  • If an underlying pulmonary, cardiac, or metabolic problem (such as asthma, pulmonary embolism, or sepsis) is the cause, diagnose and treat that condition.
  • In cases of recurrent or chronic hyperventilation, consider psychotherapy (cognitive behavioral therapy, treatment for panic disorder), respiratory rehabilitation (breathing education and biofeedback), and, if necessary, antidepressants (such as SSRIs).
• Follow-up and education
  • Patient education: Explain the symptom mechanism (hyperventilation → decreased CO2 → symptoms), practice breathing-control techniques that can be performed independently, and discuss how to respond if symptoms recur.
  • Education about emergency signs: If chest pain persists, shortness of breath suddenly worsens, or changes in consciousness or hypoxia are suspected, visit the emergency room immediately.
• Complications and precautions
  • Recurrent severe alkalinization may cause arrhythmia, fainting, reduced daily functioning, and psychogenic problems (avoidance or anxiety).
  • Do not use bag rebreathing when a hypoxic state or cardiopulmonary disease is suspected.

Checklist Before an Outpatient Visit (What to Bring and Prepare)

• Items to bring:
  • A list of all medications currently being taken (including prescription and nonprescription medications, herbal medicines, and supplements)
  • Medical history: Whether there is a history of heart disease, lung disease, epilepsy, or psychiatric diagnoses (such as panic disorder or depression)
  • Recent test results, if available: Chest X-ray, electrocardiogram (ECG), arterial blood gas (ABG), and hemoptysis or blood test results
  • Symptom records: The start time and duration of attacks, triggers (such as stress or physical activity), symptom patterns (breathing rate, tingling, fainting, etc.), and oxygen saturation (if a home pulse oximeter is available)
• Materials to show the doctor during the outpatient visit:
  • Records of heart rate, breathing rate, and oxygen saturation measured during symptoms, when possible
  • Recent emergency room visit or hospitalization records, if available
• Things to do before the appointment:
  • If attacks recur, keep a symptom diary for one week (including frequency, triggers, methods of relief, etc.)

Items that are useful to include when presenting example questions to the doctor:

• “How can we determine whether this attack is caused by a heart or lung problem?”
• “Could you demonstrate a controlled breathing technique that I can use immediately during an attack?”

Examples of General Questions to Ask the Doctor

• What are the expected effects and side effects of this medication (such as a benzodiazepine)?
• How can we distinguish whether my symptoms are caused by serious heart or lung disease?
• What lifestyle changes should I make to prevent recurrence?
• Where can I receive breathing training or psychotherapy (cognitive behavioral therapy)?
• What symptoms require me to go to the emergency room immediately?

Examples of Disease-Specific Questions

• When and how should arterial blood gas (ABG) testing and an electrocardiogram (ECG) be performed for my symptoms?
• If I have recurrent hyperventilation, what type of respiratory rehabilitation (techniques or programs) or psychotherapy (e.g., CBT or exposure therapy) is recommended? Where can I receive it?

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Note: Emergency or specialist medical care may be necessary depending on your symptoms or test results. If you have emergency symptoms such as chest pain, severe shortness of breath, or decreased consciousness, visit the emergency room immediately.