My husband is 50, no smoker, in the past 3 years he has been coughing heavily daily in the mornings, his oximeter awake reading is 89-93%. he can run, but getting very tired recently. should i insist he sees a doctor?

Yes, he needs to see a lung doctor to determine if he has a lung disease that is causing his signs and symptoms. There are many possible etiologies, including asthma. There are some forms of COPD that non-smokers can have. It is very important that he get a diagnosis so that treatment can be rendered. He will need testing, like pulmonary function testing and a chest CT. Good luck!