Chronic obstructive pulmonary disease (COPD) is an umbrella term for people with chronic bronchitis, emphysema, or both. With COPD the airflow to the lungs is restricted (obstructed). COPD is usually caused by smoking. Symptoms include cough and breathlessness. The most important treatment is to stop smoking. Inhalers are commonly used to ease symptoms. Other treatments such as steroids, antibiotics, oxygen, and mucus-thinning (mucolytic) medicines are sometimes prescribed in more severe cases, or during a flare-up (exacerbation) of symptoms.