Summer is here, and for a lot of families, that means spending time in the water.
Most people are familiar with “wet” drowning and know that it is a real risk associated with swimming and being around water. However, there is another kind of drowning that is far less common – and far more insidious, because it can happen hours after you’ve left the pool or beach.
This type of drowning is referred to as “dry” or “secondary” drowning, and while uncommon, it is important to learn how to recognize the signs and symptoms because they aren’t always obvious.
Secondary drowning happens when a person inhales water, usually due to a near-drowning incident or a sudden rush of water (as might happen when jumping into water or exiting a water slide).
From WebMD :
In secondary drowning, fluid builds up in the lungs, called pulmonary edema, after a near-drowning incident. The fluid causes trouble breathing.
A person who had a drowning close call can be out of the water and walking around normally before signs of dry drowning become apparent. But all dry drowning results in breathing trouble and brain injury, just as drowning in the water does. If untreated, it can be fatal.
Dr. Juan Fitz, a spokesman for the American College of Emergency Physicians in Lubbock, Texas, explains  how dry drowning happens in more detail:
The swimmer often appears fine immediately after the event. But over time, water left in the swimmer’s lungs begins to cause edema, or swelling, said When the lungs’ alveoli are filled with water, they cannot exchange oxygen to and from the blood. This causes the heart to slow as the swimmer’s blood oxygen level drops.
Symptoms can appear anywhere from 1 to 24 hours after the incident, and are not always easy to spot – especially in tired, young children.
Here is what to look for:
- Persistent coughing
- Shortness of breath
- Trouble breathing
- Chest pain
- Sudden mood change/change in behavior
If you notice any of those symptoms, doctors and drowning experts say to get to an emergency room immediately.
Dr. Fitz said  that if the swelling is caught early, doctors can administer oxygen and try to remove the fluid from the lungs using diuretics and positive air pressure.
If not treated, “complications will develop and will progress to pulmonary edema (evidenced by a pink frothy discharge from the victimʼs nose and mouth), hypoxia/anoxia, respiratory and cardiac arrest, and death,” according to a report  about a secondary drowning incident in 2010.
Preventing the incidents that can lead to secondary drowning can be tricky, but teaching swimmers to blow water out, know their limits, and not panic in the water can help.
It is also important to remember that “wet” drownings are usually a silent event and do not typically involve a lot of noise, splashing, or obvious distress. A person who is drowning cannot usually call for help, as they cannot obtain enough air to yell. As Alison Osinski, water safety expert and president of Aquatic Consulting Services , told CNN :
“You’re not drowning if you can call for help.”
As a reminder, here is what “active” drowning usually looks like:
In an active drowning, a swimmer is at or below eye level at the surface of the water for about 10 to 20 seconds. The head is tilted back to get air. The eyes are either wide open or tightly shut. The mouth is often in an “O” shape from shock.
After about 20 seconds, the swimmer will start to sink and will hold his breath underwater for anywhere from 30 to 90 seconds. If rescued during this time, the swimmer usually will be fine.
After 90 seconds, Osinski says, a swimmer will black out. At this point, things get dicey. If a swimmer is resuscitated after the four-minute mark, there’s a high risk of brain damage. (source )
As always, closely supervising children while they are in or around water is essential. Learning the signs and symptoms of incidents that could lead to dry drowning is just as important as knowing how to recognize the signs of active drowning.