The instinctive drowning response is an instinctive reaction that occurs in humans when close to drowning.
While distress and panic may sometimes take place beforehand, drowning itself is quick and often silent. A person at, or close to, the point of drowning is unable to keep their mouth above water long enough to breathe properly and is unable to shout. Lacking air, their body cannot perform the voluntary efforts involved in waving or seeking attention. Involuntary actions operated by the autonomic nervous system involve lateral flapping or paddling with the arms to press them down into the water in the effort to raise the mouth long enough to breathe, and tilting the head back. As an instinctive reaction, this is not consciously mediated nor under conscious control.
The lack of leg movement, upright position, inability to talk or keep the mouth consistently above water, and (upon attempting to reach the victim) the absence of expected rescue-directed actions, are evidence of the condition.
The instinct takes place for typically no longer than the final 20–60 seconds during drowning and before sinking underwater. In comparison, a person who can still shout and keep their mouth constantly above water may be in distress, but is not in immediate danger of drowning compared to a person unable to do so.
To an untrained observer, it may not be obvious that a drowning person is in distress — they may appear to be swimming safely, while actually they are within 20–60 seconds of sinking under the surface. They extend their arms laterally and press down on the water's surface in order to lift their mouths out of the water. When their mouth is above the water, they quickly exhale and inhale instead of calling for help. Because of their arm movements and their focus on lifting their mouth out of the water, they cannot wave, kick their feet, nor swim to a rescuer, nor grasp a rope or other rescue equipment. They may be misunderstood as "playing in the water" by those unfamiliar with drowning, and other swimmers just meters away may not realize that an emergency is occurring.
Lifeguards and other persons trained in rescue learn to recognize drowning people by watching for these instinctive actions.
In emergency situations in which lifeguards or other trained personnel are not present, it is advisable to wait for the victim to stop moving or sink before approaching, rescuing, and attempting to resuscitate. While the instinctive reaction to drowning is taking place, victims latch onto any and all solid objects in attempts to get air, which can result in the drowning of a would-be rescuer as well as (or instead of) the original victim. This "aquatic victim-instead-of-rescuer scenario" is common. It killed 103 would-be rescuers in Australia between 1992 and 2010, and 81 people in New Zealand between 1980 and 2012. A study of drownings in Turkey found 88 cases in which 114 would-be rescuers drowned during their attempts to rescue a primary drowning victim.