Hyperventilation is rapid or deep breathing that can occur with anxiety or panic. It is also called overbreathing, and may leave you feeling breathless.

See also: Rapid shallow breathing

When you breathe, you inhale oxygen and exhale carbon dioxide. Excessive breathing leads to low levels of carbon dioxide in your blood. This causes many of the symptoms you may feel if you hyperventilate.

Feeling very anxious or having a panic attack are the usual reasons that you may hyperventilate. However, rapid breathing may be a symptom of a disease, such as:

• Bleeding
• Heart or lung disorder
• Infection

Your doctor will determine the cause of your hyperventilation. Rapid breathing may be a medical emergency -- unless you have experienced this before and have been reassured by your doctor that your hyperventilation can be self treated.

Often, panic and hyperventilation become a vicious cycle. Panic leads to rapid breathing, and breathing rapidly can make you feel panicked.

If you frequently overbreathe, you may have hyperventilation syndrome that is triggered by emotions of stress, anxiety, depression, or anger. Occasional hyperventilation from panic is generally related to a specific fear or phobia, such as a fear of heights, dying, or closed-in spaces (claustrophobia).

If you have hyperventilation syndrome, you might not be aware you are breathing fast. However, you will be aware of having many of the other symptoms, including:

• Belching
• Bloating
• Chest pain
• Confusion
• Dizziness
• Dry mouth
• Light-headedness
• Muscle spasms in hands and feet
• Numbness and tingling in the arms or around the mouth
• Palpitations
• Shortness of breath
• Sleep disturbances
• Weakness

• Anxiety and nervousness
• Bleeding
• Cardiac disease, such as congestive heart failure or heart attack
• Drugs (such as an aspirin overdose)
• Infection such as pneumonia or sepsis
• Ketoacidosis and similar medical conditions
• Lung disease such as asthma, chronic obstructive pulmonary disease (COPD), or pulmonary embolism
• Panic attack
• Pregnancy
• Severe pain
• Situations where there is a psychological advantage in having a sudden, dramatic illness (for example, somatization disorder)
• Stimulant use
• Stress

Your doctor will look for other medical illnesses before diagnosing hyperventilation syndrome.

If your doctor has explained that you hyperventilate from anxiety, stress, or panic, there are steps you can take at home. You, your friends, and family can learn techniques to stop you from hyperventilating when it happens and to prevent future attacks.

If you start hyperventilating, the goal is to raise the carbon dioxide level in your blood, which will put an end to most of your symptoms. There are several ways to do this:

1. Get reassurance from a friend or family member to help relax your breathing. Words like "you are doing fine," "you are not having a heart attack," and "you are not going to die" are very helpful. It is extremely important that the person helping you remain calm and deliver these messages with a soft, relaxed tone.
2. To increase your carbon dioxide, you need to take in less oxygen. To accomplish this, you can breathe through pursed lips (as if you are blowing out a candle) or you can cover your mouth and one nostril, and breathe through the other nostril.

Over the long term, there are several important steps to help you stop overbreathing:

1. If you have been diagnosed with anxiety or panic, see a psychologist or psychiatrist to help you understand and treat your condition.
2. Learn breathing exercises that help you relax and breathe from your diaphragm and abdomen, rather than your chest wall.
3. Practice relaxation techniques regularly, such as progressive muscle relaxation or meditation.
4. Exercise regularly.

If these methods alone are not preventing your overbreathing, your doctor may recommend a beta blocker medication.

Call your health care provider if:

• You are experiencing rapid breathing for the first time. (This is a medical emergency and you should be taken to the emergency room right away.)
• You are in pain, have a fever, or notice any bleeding.
• Your hyperventilation continues or gets worse, even with home treatment.
• You also have other symptoms.

Your doctor will perform a careful physical examination.

To get your medical history, your doctor will ask questions about your symptoms, such as:

• Do you feel short of breath?
• What other symptoms do you have when you are breathing rapidly? Do these symptoms start at any other time (for example, when you are walking or exercising)?
• Do you have any medical conditions, such as high blood pressure, diabetes, or high cholesterol?
• What medications do you take?
• What is happening in your life in general? Has it been a particularly stressful time?
• Do you feel anxious or stressed, especially before you start breathing rapidly?
• Are you in pain? What does the pain feel like? How intense is the pain? Where is it located?
• What other symptoms do you have (for example, have you had any bleeding? Are you dizzy?)

The doctor will assess how rapidly you are breathing at the time of the visit. If you are not breathing quickly, the physician may try to induce hyperventilation by instructing you to breathe a certain way.

While you hyperventilate, the doctor will ask how you feel and watch how you breathe -- including what muscles you are using in your chest wall and surrounding areas.

Tests that may be performed include:

• Blood tests for the oxygen and carbon dioxide levels in your blood
• Chest CT scan
• ECG
• Ventilation/perfusion scan of your lungs
• X-rays of the chest

Stulbarg MS, Adams L. Symptoms of Respiratory Disease and Their Management. In: Mason RJ, Murray JF, Broaddus CV, Nadel JA, eds. Murray & Nadel's Textbook of Respiratory Medicine. 4th ed. St. Louis, Mo: WB Saunders;2005:chap 28.

Phillipson EA, Duffin J. Hypoventilation and Hyperventilation Syndromes. In: Mason RJ, Murray JF, Broaddus CV, Nadel JA, eds. Murray & Nadel's Textbook of Respiratory Medicine. 4th ed. St. Louis, Mo: WB Saunders;2005:chap 73.