About Shallow Water Blackout

Shallow Water Blackout is a silent killer:  a few minutes of your time and your understanding of the following information could save an emergency situation or even another death.

Within the UK, very little is known about Shallow Water Blackout and the risks associated with swimming underwater following exercise.  A Shallow Water Blackout is brought on when:

  • the body has been working extremely hard - exercising lowers the oxygen level in the body;
  • by taking deep breaths in preparation to swim under water, the body expels carbon dioxide from the lungs;
  • the body’s desire to breathe is brought on by a build up of carbon dioxide in the lungs - we breathe carbon dioxide out to breathe oxygen in;
  • the lungs have reduced levels of carbon dioxide, and this fools the brain into thinking that there is not yet the need to breathe;
  • the brain is low on oxygen from the initial hard exercise and this brings on a faint.

girlOn land, this faint would send oxygen racing to the brain and ‘bring round’ the patient.  However, in a swimming pool the swimmer inhales water, and without immediate aid will subsequently drown.

Learn more?


Watch our educational video featuring Sharron Davies (Olympian and TV Personality), Dr Ryk James (Forensic Pathologist) and Melanie Jeffrey whose son Luke died from drowning following a Shallow Water Blackout.