Ammonium carbonicum is a remedy that acts mainly on the respiratory system, circulation, and mucous membranes. It is especially suited to weak, sluggish, obese, or elderly individuals who are prone to congestion, faintness, and collapse. The keynote is great weakness with breathlessness, particularly at night, in warm rooms, or during exertion.

It is frequently indicated in asthma, bronchitis, pneumonia, and coryza, where the patient cannot breathe through the nose and must breathe through the mouth. The discharges (nasal, respiratory, or menstrual) are typically acrid and excoriating. It is also known as a remedy for weak heart and poor circulation, with tendency to coldness and bluish discoloration.