To help your 20-month-old son with his cough, you can give him 5 milliliters of saline water in each nostril 3 to 5 times a day for at least 3 to 5 days. This can help prevent mucus from moving to his lungs and throat. You can also give him a tablespoon of honey at room temperature before bedtime to soothe his throat. These methods may help alleviate his coughing.
