Which is best medicine for cough.?

Identify trigger: Cough is a symptom of an underlying problem. Chronic cough (>6 weeks) can come from asthma, post nasal drip from allergies, sinus infection or even stomach acid reflux. Cough can occur with a cold, whooping cough, or even a foreign body in the nose, lung, esophagus. Rather than suppress the cough with medication, see an allergist or lung specialist to identify the cause and get proper treatment.

Agree with Dr. Z: Hydrate well. Consider using a warm air vaporizer. Mix several teaspoons of honey into herbal tea with a squeeze of lemon juice. Or make tea with 2 tsp of marshmallow root bark per 1cup of hot water (steep in a covered pot for at least 5 minutes). Drink several times a day or as needed to relieve coughing. See a physician if your cough is not resolving, difficulty breathing or temp > 104.