A bit confused : I had a blood gas test... - Asthma UK communi...

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A bit confused


I had a blood gas test and the oxygen levels were normal :). What I don't understand is that the carbon dioxide levels were high. The doctor put it down to anxiety and asked me if I hyperventilate. I don't believe I do hyperventilate, although I do experience anxiety and depression. I also experience frequent tiredness, dizziness and headaches. I have had asthma for over 40 years and experience frequent shortness of breath. Does anyone else experience this?


4 Replies

Your carbon dioxide levels were high and he said it was anxiety??

Hyperventilation is very common, especially when we are anxious or panicked about something or when we are having an asthma attack.

Normally when people have asthma attacks or are hyperventilating (breathing >20 breaths per minute) the carbon dioxide levels go low. This is because we are blowing off CO2. If someone has COPD then their CO2 levels can often be on the higher side which is fine but if someone is having an asthma attack and their CO2 levels are normal/high or high that can be quite concerning to be honest and indicates they need more help with their breathing.

Tiredness and headaches can be quite common in people with asthma because of the frequent shortness of breath episodes you are talking about. Do you happen to know if your haemoglobin levels are okay? Tiredness, headaches and dizziness with shortness of breath (especially if when walking, etc) can also be a symptom of anaemia...though I would imagine that if they did a blood gas test on you they would also have taken normal bloods and this would have been picked up on.

All of this I wrote though is based on the assumption that the blood gas test was done in hospital when you had an exacerbation?

Hidden in reply to Hidden

Thanks for your reply.

Yes all blood tests where done in hospital and were normal with the exception of carbon dioxide.

I have asthma and attended a&e with shortness of breath and chest heaviness. My sats were normal. He said that worry would cause the abnormal result. Thanks.

Hidden in reply to Hidden

Yea, sats can be normal in people having as asthma attack but because the blood gas test is more accurate the doctors do that to get a better idea (it also shows oxygen levels as well as the CO2 levels and pH of the blood which is important to determine how much treatment you need).

Haven't heard of anxiousness causing CO2 but I guess if he thought that was what it was and you are getting better now then it must be okay?

Hope you are improving anyway :) Take care.

Hyperventilation causes high oxygen levels and low carbon dioxide - which is why people are asked to 'rebreathe' into a paper bag or cupped hands when having a panic attack. Asthma (or any restrictive breathing) can cause higher carbon dioxide levels because the lungs do not breathe out as efficiently and so leave the de-oxygenated air in our bodies. I think your doc needs to revise his physiology!!

I would go back to see him or ask for a second opinion :)

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