Respiratory distress syndrome (RDS) is a common lung condition in premature infants born before 37 weeks. RDS is caused by a shortage of pulmonary surfactant, a liquid that helps keep air sacs in the lungs called alveoli open. Babies with RDS tend to breathe fast, grunt, or make an "ugh" sound with each breath and their nostrils may flare. There are several treatment options for RDS including delivering oxygen through a nasal cannula, use of continuous positive airway pressure (CPAP) machines to push air into the lungs, surfactant delivered directly to the lungs via intubation for severe cases, and medications to calm infants during intubation.