You take a deep breath. Your chest is full of air. But something inside you still says: I need more air, now. That feeling has a name. It’s called air hunger.
It’s a real thing, and doctors have known about it for years. But more people know the term today because of Howard Cooper, an anxiety therapist in the UK. He has helped raise awareness of this and made it better understood. You can watch him explain it in his video, The Physiology of Low CO₂ Air Hunger. We’re sharing this as a helpful explanation of the physiology, not as a treatment method we’ve assessed or are recommending you follow.
Here’s what is really happening in your body, in simple terms.
What’s going on inside you
Air hunger is usually not a problem with your lungs. It’s not a problem with oxygen either. It’s about a gas called carbon dioxide, or CO₂.
You breathe out too much CO₂. If you breathe fast or deep, more than your body needs, you get rid of CO₂ too quickly. The CO₂ level in your blood drops.
Your blood holds on to its oxygen. Your blood carries oxygen using something called haemoglobin. Haemoglobin needs CO₂ to let go of oxygen easily. When CO₂ is too low, haemoglobin grips the oxygen tighter. Less oxygen reaches your brain and the rest of your body, even though your lungs are full.
Your blood vessels get narrower. Low CO₂ also makes your blood vessels tighten up, including in your brain. This can make you feel dizzy, tingly, or lightheaded.
Your brain sounds a false alarm. Your brain checks your CO₂ level to decide how badly you need to breathe. When CO₂ drops too fast, your brain can panic. It sends a strong signal that you are suffocating, even though you have plenty of air.
So this is why you can feel like you’re suffocating, even while breathing totally normal air. The panic feeling is real. But your body isn’t actually short of air.
What causes it
A few common habits can bring on air hunger:
- Fast breathing and anxiety. Quick, shallow breaths from your chest, or lots of sighing, use up your CO₂ too fast.
- Breathing through your mouth. This changes how much air you breathe in and out. Over time, it makes you more sensitive to low CO₂.
- Warning signs. Cold hands and feet, feeling dizzy, tingling or numb skin, and a strong urge to gulp in air are all common signs that go along with it.
What can help
If you feel air hunger, taking a big deep breath often makes it worse. It lowers your CO₂ even more. What actually helps is the opposite: breathing slowly and gently through your nose. Over time, this can help your body get used to slightly higher CO₂ levels. Howard Cooper’s video and a method called Buteyko breathing both explain this in more detail.
A quick but important note
Feeling short of breath can have many causes. Some need to be checked by a doctor, such as problems with your heart or lungs, or low iron in your blood. Some of these need quick attention. Air hunger caused by fast breathing can be an explanation, but only once other causes have been checked and ruled out.
If your breathlessness is new, getting worse, comes with chest pain or a racing heart, or wakes you up at night, please contact us and book an appointment. Don’t just assume it’s air hunger. If you already know this is your pattern and want help with breathing techniques, we’re happy to support you with that too.
This article is for general information only. It is not a diagnosis and does not replace an individual assessment. If you’re worried about your symptoms, please contact the practice.