In simple terms, what happens during rapid decompression?

Air at sea level will expand to 5 times its volume at 40,000ft. Lung capacity is approximately 6 liters. Therefore, during rapid decompression, a continuous exhalation is experienced. Holding one’s breath may result in bursting of the lungs. Persons suffering from asthma or partially blocked lung passage due to age may be adversely affected by a rapid decompression.