Barrel chest generally refers to a broad, deep chest found on a man. A man described as barrel chested will usually have a naturally large ribcage, very round torso, large lung capacity, and will potentially have lots of upper body strength. It can sometimes be a sign of acromegaly (a syndrome resulting from excess levels of Growth Hormone in the body).
Barrel chest also refers to an increase in the anterior posterior diameter of the chest wall resembling the shape of a barrel, most often associated with emphysema. There are two main causes of the barrel chest phenomena in emphysema: