OVERVIEW

What is pulmonary ventilation?

Pulmonary ventilation refers to the process where external air enters the lungs, allowing the lungs to inhale fresh oxygen and exhale internal gases (containing higher levels of carbon dioxide and lower levels of oxygen). This entire process is known as gas exchange.

During respiration, does the human body exhale only carbon dioxide without any oxygen? Is there carbon dioxide in the body?

Although we often describe breathing as the process of inhaling oxygen and exhaling carbon dioxide, in reality, oxygen and carbon dioxide coexist both in the air and within our bodies.

Our bodies require oxygen to maintain normal functions, but they also need carbon dioxide to stabilize the internal environment. When excess carbon dioxide is produced in the body, it is expelled through respiration.

What is hyperventilation?

Hyperventilation occurs when increased respiratory depth or frequency leads to excessive expulsion of carbon dioxide beyond normal physiological levels. This can cause symptoms such as dizziness, chest tightness, and difficulty breathing, collectively known as hyperventilation syndrome. It has also been referred to as hyperventilation syndrome or high-ventilation syndrome.

Although most carbon dioxide in the body is expelled as waste, it is not entirely useless. The body requires a certain amount of carbon dioxide to maintain normal physiological functions, and both excessive or insufficient levels can cause discomfort.

Is hyperventilation the same as difficulty breathing?

Hyperventilation can cause difficulty breathing, as well as symptoms like dizziness and limb numbness. However, difficulty breathing is merely a symptom that can also result from other conditions, such as cardiopulmonary diseases. Therefore, equating hyperventilation with difficulty breathing is incorrect.

Is hyperventilation a form of hysteria or a mental disorder?

Psychological factors such as tension, anxiety, or anger are significant triggers for hyperventilation. For this reason, it was once referred to as hysterical hyperventilation syndrome.

SYMPTOMS

What are the manifestations of hyperventilation?

Due to factors such as tension, environmental hypoxia, or illness, changes in breathing depth and speed may occur, leading to symptoms such as chest tightness, chest pain, palpitations, difficulty breathing, dizziness, headache, numbness in the hands, feet, or face, hand and foot cramps, blurred vision, fatigue, weakness, and reduced exercise tolerance. When these symptoms occur, they may indicate hyperventilation.

Hyperventilation patients may also experience emotional distress. While focusing on symptom relief, do not neglect emotional well-being. Lifestyle changes such as meditation and exercise can help improve mood, and psychological counseling can also assist in resolving emotional difficulties.

Additionally, patients in this state often need support and understanding, so care from family and friends can be very helpful.

Why does hyperventilation cause apnea?

To restore normal carbon dioxide levels, the brain directs us to breathe rapidly to expel excess carbon dioxide.

However, excessively rapid breathing has adverse effects on the body, leading to a significant decrease in carbon dioxide levels. As a result, the brain (though not consciously) reacts by stopping these actions, causing apnea. As carbon dioxide levels gradually rise, the brain then directs the body to resume normal breathing.

Why do hyperventilation patients feel breathless even though they are not actually hypoxic?

Due to anxiety or fear, patients may breathe rapidly and intensely in an attempt to alleviate these psychological reactions. However, overly rapid breathing triggers the body's counter-response, slowing or even stopping breathing. This contradictory state makes hyperventilating individuals feel as though they cannot get enough air.

What are the dangers of hyperventilation?

Severe hyperventilation can lead to low blood pressure, insufficient blood supply to the brain, and even sudden fainting.

Is hyperventilation life-threatening?

Generally, no.

During a hyperventilation episode, patients may experience symptoms such as rapid heartbeat, sweating, dizziness, and hand numbness, which often resolve on their own. However, if these symptoms persist, worsen, or are accompanied by severe dizziness, confusion, or difficulty speaking, immediate medical attention is necessary to prevent fainting or other complications.

What kind of rapid breathing is dangerous?

The most dangerous situation is when rapid breathing is accompanied by bluish lips or skin, cold sweats, or fainting. Immediate medical care is required in such cases.

Why does hyperventilation cause fainting?

Hyperventilation can slow the heart rate and dilate blood vessels, leading to low blood pressure and insufficient oxygen supply to the brain, resulting in loss of consciousness. While recovery often occurs spontaneously, it is difficult to determine the cause of fainting, so emergency medical attention is still advised.

Does hyperventilation affect children's intelligence?

Hyperventilation reduces carbon dioxide levels in the blood, causing symptoms such as respiratory disturbances, palpitations, chest tightness, and dizziness. However, it typically does not affect children's intellectual development. If hyperventilation is caused by another underlying condition, attention should be paid to whether the primary disease affects intelligence.

CAUSES

How does hyperventilation occur?

The mechanism of hyperventilation is not yet fully understood. Studies suggest that physical stress is a major contributing factor, such as tension, anxiety, or panic, which accelerates breathing rate and increases depth, leading to difficulty breathing. This respiratory distress, in turn, exacerbates psychological changes like tension and anxiety, creating a vicious cycle.

Although hyperventilation episodes may cause breathing difficulties, these symptoms gradually improve as mental and emotional states stabilize. In contrast, genuine breathing difficulties are often caused by medical conditions such as asthma or chronic obstructive pulmonary disease (COPD), which typically do not resolve on their own and require medication to alleviate symptoms.

What causes hyperventilation?

Research indicates that hyperventilation is primarily triggered by psychological factors such as tension, fear, excitement, crying, or excessive fatigue. Additionally, conditions like lung infections, hypovolemia, electrolyte imbalances, heart disease, cerebral ischemia, or heightened neural sensitivity can also lead to hyperventilation.

Who is more prone to hyperventilation? Are there specific psychological traits?

• Aged between 15 and 55 years;

• More common in women than men, particularly those prone to tension or fear.

Is hyperventilation hereditary?

Hyperventilation syndrome is mostly caused by psychological factors like stress or anxiety and is generally not hereditary.

DIAGNOSIS

How to Determine Hyperventilation?

• Preceding episodes often involve triggers such as mental tension, fear, anxiety, or fatigue;

• Common symptoms include dizziness and difficulty breathing;

• If the above conditions are present, a hyperventilation provocation test can be performed at a hospital. A positive result suggests possible hyperventilation.

If all the above criteria are met, hyperventilation can be diagnosed. If only one criterion is met, it is considered suspected hyperventilation.

How to Accurately Assess Hyperventilation?

Assessment can be conducted via questionnaires, such as the Nijmegen Questionnaire, which is designed for hyperventilation syndrome and lists 16 common symptoms, including chest pain, tension, blurred vision, dizziness, confusion, chest tightness, shortness of breath, bloating, finger numbness, difficulty breathing, stiff arms/fingers, tightness around the lips, cold hands/feet, palpitations, and anxiety. Individuals can evaluate their condition based on these symptoms.

Each symptom is scored from 0 to 4 (none, rare, occasional, frequent, very frequent). A total score of 23 or higher indicates possible hyperventilation.

What Is a Hyperventilation Provocation Test?

The hyperventilation provocation test is one method to diagnose hyperventilation, typically performed when hyperventilation is suspected to aid in diagnosis.

• A doctor guides the patient to intentionally deepen and quicken their breathing to artificially induce hyperventilation.

• The patient's sensations and symptoms during this breathing state are recorded.

• If hyperventilation-related symptoms occur, the test is positive. If no discomfort is experienced, the test is negative.

TREATMENT

Can hyperventilation be cured?

There are many causes of hyperventilation. If it is caused by diseases such as asthma or chronic obstructive pulmonary disease (COPD), treatment should target the underlying condition, which can effectively alleviate symptoms caused by hyperventilation.

If it is solely due to psychological or emotional factors, interventions such as psychotherapy combined with medication can help. Consistent treatment can control the severity and frequency of recurrence, potentially maintaining long-term stability without episodes.

What breathing method is better for hyperventilation patients?

Diaphragmatic (abdominal) breathing is recommended as more beneficial. This involves the abdomen expanding during inhalation and gradually returning during exhalation. Slow, deep breathing can effectively relieve discomfort caused by hyperventilation.

Should you breathe into a paper bag during hyperventilation?

Breathing into a paper bag or covering the head with one is not advised. The diagnostic or therapeutic value of this method—promoting carbon dioxide rebreathing to observe rapid symptom relief—remains debatable.

Rebreathing carbon dioxide may lead to hypoxemia, and this method could cause adverse outcomes in adult patients with underlying respiratory or cardiovascular conditions.

Additionally, in patients with hyperventilation caused by metabolic acidosis, breathing into a paper bag may disrupt the body's respiratory compensation, potentially worsening acute acidosis.

How should hyperventilation be treated?

During the acute phase, doctors focus on reassuring patients and explaining the symptoms they are experiencing. Patients should remain calm.

Next, remove stressors and initiate breathing retraining. During an acute episode, breathing retraining can focus on diaphragmatic (abdominal) breathing:

• Sit or lie down (lying down is usually easier). Place one hand on the abdomen and the other on the chest, observing which hand moves more (in hyperventilation patients, the hand on the chest typically moves more).
• Adjust breathing so the hand on the abdomen moves more, while the hand on the chest remains as still as possible.
• First-time patients may panic and struggle to cooperate, requiring doctor guidance. Instruct them to take a deep breath, hold it, and exhale slowly to ease anxiety—inhale slowly for 4 seconds, hold for a few seconds, then exhale for 8 seconds. After 5–10 cycles, patients should feel calmer, with reduced anxiety and improved hyperventilation.
• Ideally, symptoms should ease as breathing training continues.

If these methods don’t fully resolve the episode and severe symptoms persist—or if symptoms like tetany or spasms occur—the patient should be taken to the hospital promptly.

In the hospital, low-dose short-acting benzodiazepines may be administered.

DIET & LIFESTYLE

What should hyperventilation patients pay attention to in daily life?

• Maintain a happy mood. If encountering unpleasant situations, release negative emotions through music, yoga, travel, chatting with friends, etc., to relax both body and mind;

• Keep the environment warm and cozy, avoiding dark, cramped, or depressing places;

• When noticing rapid breathing, try to control your breath, practice diaphragmatic breathing, and adopt deep, slow breathing to alleviate discomfort.

What dietary precautions should hyperventilation patients take?

• Most fresh fruits can be consumed, but be cautious with fruits like peaches that may irritate the throat or cause allergies or swelling—limit intake;

• Follow a light diet. Avoid spicy or stimulating foods if they cause discomfort, and be cautious with allergenic foods like seafood;

• Quit smoking and limit alcohol to maintain a healthy lifestyle.

Can hyperventilation patients engage in strenuous activities?

The main symptom of hyperventilation is altered breathing. Deep and rapid breathing can easily cause dizziness, numbness in the hands and feet, etc. Strenuous activities may trigger excessive breathing, leading to hyperventilation and these symptoms. Therefore, it is recommended that hyperventilation patients avoid intense activities.

Start with gentler exercises like yoga, walking, or tai chi, and gradually increase intensity.

PREVENTION

Can Hyperventilation Be Prevented?

• The first step to reduce the risk of recurrent acute episodes of hyperventilation syndrome should be initiating a breathing retraining program. The breathing exercises mentioned above should be performed twice daily, in the morning and evening. Breathing retraining guidance can be provided by a respiratory therapist, a physiotherapist from a pulmonary rehabilitation program, or another qualified professional.

• If symptoms recur after undergoing breathing retraining, cognitive behavioral therapy from a psychiatric or rehabilitation department can be considered.

• If severe hyperventilation episodes persist after the above two steps, pharmacological intervention is necessary, with treatment guided by a psychiatrist.