When do you get copd? can it happen as soon as 9 or younger? what causes it and is it preventable or curable?

Usually older: Although some "obstructive diseases" like bronchiectasis can occur early in childhood, COPD (chronic obstructive pulmonary disease) by definition usually takes decades to develop. It is almost always associated with smoking or heavy passive smoke/industrial exposures. Once developed, there is no cure, but lung function decline can be slowed with smoking cessation. Inhaled meds can help symptoms.

Rarely: Rarely that young unless you have Alpha 1 antitrypsin disease...Don't smoke!