Hello, often times I feel as if I am not taking in enough oxygen when I inhale. I feel the need to yawn to fill my lungs, and it is not always successful. There is a slight feeling of tightness or stiffness in my throat, it is as if the oxygen does not fully pass through the airway. It is not ,a shortness of breath, no other physical symptoms seem obvious, but it is very uncomfortable. I notice it is more frequent when I am very tired. What could this potentially be/be indicating?