Most drownings occur in water, 90% in freshwater (rivers, lakes and pools) 10% in seawater, drownings in other fluids are rare and often industrial accidents.

Common conditions and risk factors that may lead to drowning include but are not limited to:

• Males are more likely to drown than females, especially in the 18-24 age bracket.
• Failing to wear a PFD when boating.
• Lack of supervision of young children (less than 5 years old).
• Water conditions exceed the swimmer’s ability – turbulent or fast water, water out of depth, falling through ice, rip currents, undertows, currents, waves and eddies.
• Entrapment – physically unable to get out of the situation because of a lack of an escape route, snagging or by being hampered by clothing or equipment.
• Impaired judgment and physical incapacitation arising from the use of drugs, principally alcohol.
• Incapacitation arising from the conditions – cold (hypothermia), shock, injury or exhaustion.
• Incapacitation arising from acute illness while swimming – heart attack, seizure or stroke.
• Forcible submersion by another person – murder or misguided children’s play.
• Snowmobiling after dark.
• Blackout underwater after rapid breathing to extend a breath-hold dive – shallow water blackout.
• Blackout on ascent from a deep breath-hold dive due to latent hypoxia – deep water blackout.

People have drowned in as little as 30 mm of water lying face down, in one case in a wheel rut. Children have drowned in baths, buckets and toilets; inebriates or those under the influence of drugs have died in puddles. For a more detailed list of causes see swimming.