急性細支氣管炎常見於二歲以下的小朋友，由病毒感染造成。最常見者為呼吸道融合病毒，其他包括副流行性感冒病毒、流行性感冒病毒、腺病毒或黴漿菌等。
在開始三至五天，會以上呼吸道症狀，如咳嗽或流鼻水為表現。接著會有發燒，呼吸急促，甚至有多痰及「咻咻」的喘聲。咳嗽和呼吸困難發作後48-72小時內，出現呼吸危險的風險最高，但因此而致命的比例小於1%。症狀持續約二星期，有十分之一的小朋友可能會達到三星期。得過此病未來得到氣喘的機會上升。
During the first three to five days of illness, symptoms typically involve the upper respiratory tract, such as coughing and a runny nose. These symptoms may then be followed by fever, rapid breathing, and even excessive mucus production and wheezing. The risk of respiratory distress is highest within 48–72 hours after the onset of coughing and breathing difficulties, but the mortality rate is less than 1%. Symptoms usually last about two weeks, although approximately one in ten children may remain symptomatic for up to three weeks. Children who have had bronchiolitis have an increased risk of developing asthma later in life.
治療上需要補充水分，若住院者，可給予氧氣帳。其他藥物的使用，在最新實證醫學上並無證據支持。預防總是勝於治療。均衡的營養、良好的衛生、勤洗手、避免公共場所暴露都可以減少得到急性細支氣管炎的機會。
Treatment focuses on maintaining adequate hydration. For hospitalized patients, an oxygen tent may be used to provide supplemental oxygen. According to the latest evidence-based medical research, there is no evidence supporting the routine use of other medications. Prevention is always better than treatment. A balanced diet, good hygiene, frequent handwashing, and avoiding exposure in public places can all help reduce the risk of acute bronchiolitis.
