asthma

How is it possible that when i am having a serious asthma attack, my oxygen measurement is excellent?

[National Jewish Health]

Because asthma is a disease of the airways, not of that part of the lungs where gas exchange occurs, oxygen-in and carbon dioxide-out.  Normal, young lungs can usually extract enough oxygen from the inhaled air, even when the obstruction to airflow is marked.  A fall in blood oxygen, during an asthma attack is a serious medical emergency and may necessitate mechanically assisted ventilation.

Thus, the fact that your oxygen measurement "is excellent" is a good sign.  Given that, one should not interpret a normal value as a sign that the asthma attack is not severe.

[hilary86]

I have this happen too and I glad to hear that it can happen because when I go to the ER for a bad asthma attack they say you are not because your oxygen is fine