Expectorant herbs (those that help expel mucus) clear the airways and promote deep, expansive breathing. Emollient herbs (those that soothe irritated tissues) relieve cough and increase resistance to infections. Antispasmodic herbs (those that relieve spasms) reduce the strength and frequency of coughing fits, increase blood circulation in the thoracic region and the air circulation in the lungs. To treat the respiratory tract with herbs, we use extracts for immediate results, and we add herb teas for long-lasting effects.