Elderly phlegm remedies can be divided into two types according to their mode of action, including nauseating expectorants and phlegm dissolvers, with specific efficacy varying from person to person, and there is no such thing as which one is better. 1. Nauseating expectorants, including ammonium chloride. Due to the chemical stimulation of the gastric mucosa, reflexively increase the amount of sputum, so that sputum is easy to discharge; in addition, after the product is absorbed, part of it is discharged from the respiratory tract, due to the osmotic pressure effect of the respiratory tract water increases, so that sputum dilution is easy to cough out. Adverse reactions for a large number of doses can cause nausea, vomiting, thirst, stomach pain. It is contraindicated in patients with ulcerative diseases. 2. Sputum dissolving agents, including bromhexine hydrochloride, etc. This product has a strong effect of dissolving mucous phlegm, so that sputum can be easily coughed up. Occasional nausea and stomach discomfort may disappear after dosage reduction or discontinuation of the drug. It should be used with caution in patients with gastritis or gastric ulcer. All drugs should be taken under medical supervision, if there is any discomfort promptly consult a doctor.