[Course of obstructive lung diseases].

Obstructive lung disease can be divided into bronchial asthma and chronic obstructive lung disease. Forced expiratory volume for one second (FEV1) is the most commonly used variable to follow the course of obstructive lung disease. In healthy who have never smoked, FEV1 reaches a plateau phase at the age of 20-35 years, before starting to decrease with increasing age. In subjects with obstructive lung disease this plateau phase does not exist and the decline in FEV1 is steeper than in healthy subjects. Asthmatics who stop smoking, double the probability of remission of the disease. Remission of occupational asthma is dependent on early diagnosis of the disease. The disease seems to follow a more benign course in asthmatics with an allergic disposition than asthmatics without. The effect of a bronchodilator and antiinflammatory treatment on the course of obstructive lung disease is not known. Long-term oxygen therapy is the only treatment that clearly effects survival in patients with chronic obstructive lung disease.