In byssinosis the initial lesion is an acute bronchioloitis associated with symptoms and signs of generalised airflow obstruction. Which tend to be worse after the weekend break, but eventually become continuous. There is no radiological abnormality. Recovery usually follows removal from exposure to the dust hazard. Smokers have e greater incidence of byssinosis than non-smokers and smoking should be discouraged in all workers at risk. In chronic disease the treatment is similar to that for patients with chronic obstructive bronchitis.