The main causes of neonatal pulmonary hemorrhage include: 1, lack of oxygen: the most common inside the neonatal pulmonary hemorrhage, such as choking and suffocation or lung inflammation in hospitalized small children is very heavy, bad breathing, if there is no active treatment, slightly prolonged, may be complicated by pulmonary hemorrhage; 2, infection: such as serious infection of small children, lung condition is very heavy, the systemic condition is also very heavy, also easy to appear pulmonary hemorrhage; 3, cold Injury: for example, the weather is particularly cold, and small children have a very low body temperature, coupled with some primary diseases, they are prone to pulmonary hemorrhage. For example, when watching movies, you often see mountain climbing, and in very cold conditions such as snowy mountains, pulmonary hemorrhage and hemoptysis can easily occur. The above 3 causes are the most common causes of pulmonary hemorrhage, but of course there are other causes of pulmonary hemorrhage, such as less developed lungs, which have a higher likelihood of pulmonary hemorrhage. There are also other factors, such as acidosis. In addition, when other diseases are combined, such as neonatal respiratory distress syndrome, the probability of pulmonary hemorrhage is also higher.