Why Does Drinking Seawater Kill You Faster Than Non-Seawater?

Many old sea legends tell the tale of some poor stranded sailor who drinks seawater and goes mad or even dies. Seawater poisons your body and drinking too much salty water can be fatal. Drinking too much fresh water can also be harmful, but only in extreme quantities. Drinking seawater will kill you much faster than fresh water.

Balance

• Every function the body performs---from blinking to thinking and everything in between---relies on a delicate balance between the substances inside the cells and the substances outside the cell membranes. These substances include proteins, salts and fluids. Some substances are able to move in and out of cells as necessary. Water moves very easily across the cell membrane.

What Happens When You Drink Seawater

• Seawater is about three times saltier than blood. Drinking seawater floods the body with salt and destroys the crucial balance of substances inside and outside of the cell. The body goes into crisis mode. Water from inside the cells leaks out to dilute the salt and flush it out of the body. The cells lose too much water and dehydrate.

Effects of Drinking Seawater

• Symptoms include nausea and vomiting, swelling of the limbs and hallucinations. Symptoms can also include seizures, coma, brain damage and kidney failure, depending on the amount of seawater consumed.

Water Intoxication

• Fresh water is only dangerous in very large quantities.

  Fresh water can also disturb the balance of substances inside and outside the cells, but only in very large quantities. This condition is known as hypoatremia, or water intoxication. Though too much salt is deadly, the body does require some salt to survive. Large amounts of fresh water will flush too much salt outside the body.

Hypoatremia Effects

• Symptoms include nausea, slurred speech, disorientation and muscle cramps. In extreme cases water intoxication causes seizures, coma, brain damage and death.

Considerations

• Water intoxication is rare. It is important to provide your body with enough water each day---don't let fear of water intoxication cause you to dehydrate yourself. Water intoxication most commonly affects athletes who have lost salt through sweat. Drinking seawater is dangerous. Swallowing a little seawater at the beach will not kill you, but you should never deliberately drink salt water.