Has it always been this way? Were you ever a smoker or lived with one, or worked in a dusty/polluted environment? Have allergies?
Perhaps it's something related to advanced age, or you have a weakened immune system.
Remedy: consult your primary care doctor or see an ENT specialist, or pulmonary specialist.
Home remedies might have some limited help at times. Some people swear by echinacea herbal supplements and/or certain vitamin supplements.
Currently there's a serious bronchial infection ... possibly influenza that is rampant.