Do Lungs Continue To Develop After Birth?

Yes, our lungs continue to grow and develop after we are born. In particular, the specialized gas-exchanging lung units called alveoli, where oxygen is exchanged for carbon dioxide, develop postnatally. The majority of the lung alveoli—nearly 85%—are in fact formed after birth, during the first 3 years of life.

The blood supply within the capillary network matures in parallel with alveolar devel-opment from birth to 3 years of age. Mucus cells that line the air passages also develop after birth. Because the majority of alveoli develop postnatally, the first 3 years of life after birth can be viewed as an especially vulnerable period.

Experts believe that poorly controlled asthma in childhood and adolescence may be responsible for reduced lung capacity and lessened lung function throughout life. In addition to controlling childhood asthma, it is crucial that babies and children be raised in smoke-free homes to maximize normal lung maturation.After the age of 3, the lungs are formed, but not fully grown. As our bodies develop through adolescence to adulthood, so too, do our lungs.

Adolescence represents a second vulnerable window. Recent scientific studies indicate that teenagers who smoke are left with lung function that is less than that of healthy nonsmoking teens. The finding of stunted lung function development in adolescent smokers is especially notable in girls.