My husband since 3:00am he has a pounding feeling in the left side of his face doesn't have a stoped up nose can breathe just fine what can it be?

Maybe migraine: This could be the beginning of a form of migraine headache. Most often one-sided, can "feel" as if it's coming from the sinus area. Other symptoms would include nausea, sensitivity to light and/or sound. Short term therapy would be anti-inflammatories like Advil/ibuprofen. If these are happening frequently see a doctor, there are specific treatments and prevention for migraine in many cases.