Drowning is defined as respiratory impairment as a result of being in or under a liquid. Drowning typically occurs silently, with only a few people able to wave their hands or call for help. Symptoms following rescue may include breathing problems, vomiting, confusion, or unconsciousness. Occasionally symptoms may not appear until up to six hours afterwards. Drowning may be complicated by low body temperature, aspiration of vomit, or acute respiratory distress syndrome.

Drowning is more common when the weather is warm and among those with frequent access to water. Risk factors include alcohol use, epilepsy, and low socioeconomic status. Common locations of drowning include swimming pools, bathtubs, natural bodies of water, and buckets. Initially the person holds their breath, which is followed by laryngospasm, and then low oxygen levels. Significant amounts of water usually only enter the lungs later in the process. It may be classified into three types: drowning with death, drowning with ongoing health problems, and drowning with no ongoing health problems.

Efforts to prevent drowning include teaching children to swim, safe boating practices, and limiting or removing access to water such as by fencing pools. Treatment of those whose who are not breathing should begin with opening the airway and providing five breaths. In those whose heart is not beating and who have been underwater for less than an hour CPR is recommended. Survival rates are better among those with a shorter time under the water. Among children who survive, poor outcomes occur in about 7.5% of cases