Hyperventilation and Hypoventilation

Written by Jim Folk
Medically reviewed by Marilyn Folk, BScN.
Last updated November 20, 2021

A change in blood oxygen (CO2) level, either too much or too little, can cause many anxiety-like symptoms,[1][2][3][4][5] including:


  • Anxious feeling
  • Belching or bloating
  • Chest pain or tightness
  • Dry mouth
  • Faster than normal heartbeat
  • Feeling as if you can't catch your breath
  • Feeling faint, dizzy, weak, or lightheaded
  • Feeling that air is not getting into the lungs
  • Frequent yawn or sighs
  • Headache
  • Involuntary panic attacks
  • Muscle spasms in the hands and feet
  • Neuronal excitation[6]
  • Not able to think straight
  • Numb, tingly feeling in your hands or feet
  • Numbness and tingling in the arms or around the mouth
  • Numbness or tingling in the fingers
  • Pounding heart
  • Problems sleeping
  • Shortness of breath, or feeling that you can’t get enough air


  • Anxious feeling
  • Bluish coloration of the skin caused by lack of oxygen
  • Bluish-colored lips, fingers, or toes
  • Blushing
  • Confusion
  • Daytime drowsiness, sleepiness
  • Delirium
  • Depression
  • Disorientation
  • Dizziness, lightheadedness
  • Fatigue, tiredness
  • Headaches
  • High or low blood pressure
  • Involuntary panic attacks
  • Muscle weakness
  • Nausea
  • Rapid heart rate
  • Reduced pupils
  • Seizures
  • Shallow breathing
  • Shortness of breath
  • Slow and shallow breathing
  • Swelling of the ankles
  • Tremors
  • Vomiting
  • Waking up from sleep unrested
  • Waking up many times at night

As hyperventilation and hypoventilation relate to anxiety, when you are stressed, anxious, or think you are in danger, stress hormones are released into the bloodstream. Stress hormones cause the body to change its breathing patterns from slow, deeper breaths to either rapid, deeper breaths (hyperventilation) or to rapid, shallow breaths (Tachypnea).

When your breathing changes to either of these patterns, carbon dioxide (CO2) levels in the blood change.

Hyperventilation causes lower levels of CO2. Low levels of CO2 can cause you to feel lightheaded, dizzy, woozy, and faint, which can trigger an instinctive fear reaction. This fear reaction can be sufficient to cause a high degree stress response similar to that of a panic attack.

Moreover, some people hold their breath or under breathe when they are stressed or anxious, which can cause hypoventilation (not enough oxygen). Not enough oxygen increases CO2 in the blood, which can cause the sensations of feeling lightheaded, dizzy, woozy, and faint, which can also be sufficient to cause an involuntary high degree stress response (panic attack).

Both hyperventilation and hypoventilation can cause many anxiety-like symptoms, including involuntary panic attacks.[6][7]

Changing your breathing to a normal pattern can restore healthy CO2, which will eliminate symptoms of hyperventilation or hypoventilation.

If you are sensitive to the feelings of anxiety or hyperstimulation, or their symptoms, we don’t recommend deliberately invoking hyperventilation or hypoventilation.

It’s best to maintain a normal relaxed breathing pattern whenever you are consciously aware of your breathing.

The combination of good self-help information and working with an experienced anxiety disorder therapist, coach, or counselor is the most effective way to address anxiety and its many symptoms. Until the core causes of anxiety are addressed – which we call the underlying factors of anxiety – a struggle with anxiety unwellness can return again and again. Dealing with the underlying factors of anxiety is the best way to address problematic anxiety.

Additional Resources

Return to our anxiety disorders signs and symptoms page.

anxietycentre.com: Information, support, and therapy for anxiety disorder and its symptoms, including Hyperventilation and Hypoventilation.


1. “Hyperventilation.” MedlinePlus, 28 June 2018.

2. “Respiratory depression: Causes, symptoms, and treatment.” Medical News Today, 21 Aug. 2017.

3. Duinen, Marlies, et al. "CO2 challenge induced HPA axis activation in panic." International Journal of Neurophsyopharmacology, 2007.

4. Tavel, Morton E. "Hyperventilation Syndrome: A Diagnosis Usually Unrecognized." HSOA Journal of Internal Medicine & Primary Healthcare." 29 July 2016.

5. Zhang, et al. "Hyperventilation in neurological patients from physiology to outcome evidence." Current Opinion in Anesthesiology, Oct 2019.

6. Nardi, Antonio, et al. "Panic disorder and hyperventilation." PubMed, Dec 1999.

7. Meuret, Alicia E., and Thomas Ritz. “Hyperventilation in Panic Disorder and Asthma: Empirical Evidence and Clinical Strategies.” NCBI PubMed, U.S. National Library of Medicine, Oct. 2010.