My daddy is 79 years old he was diagnosed with double pneumonia. He is home now can home with oxegen. Was wondering how long it will be till he is back to what he use to be. He was a very active man, cooked, took care of my mom played hours with his 3 great grandkids. Now he is weak has lose 8 pound is always tired. My oxegen level is 97 with oxegen on. Have not checked it without the O2 on.