If so, you should avoid such physical activity temporarily. Active and passive smoking Don't be around anyone who smokes. Also avoid smoking since a cough may last weeks longer than it would without smoking. Common mistakes in treating cough Antihistamines, decongestants, and antipyretics are found in many cough syrups. There is no proof that these ingredients will help your cough, and the antihistamines may make you sleepy.
Expectorants are of unproven value but harmless.
Milk does not need to be eliminated from the diet. Restricting it improves the cough only if you are allergic to milk. The cough lasts more than 3 weeks. You have other concerns or questions.