Drinking salt water is harmful because seawater contains a much higher concentration of salt than human blood—about four times saltier. When salt water is consumed, the excess salt causes water to be drawn out of the body's cells into the bloodstream by osmosis. This dehydration at the cellular level can cause severe dehydration, affecting brain function and leading to symptoms like vomiting, delirium, and even death. Additionally, human kidneys cannot produce urine saltier than blood, so to expel the excess salt, the body must use more water than the volume of salt water consumed, worsening dehydration. The excess salt also increases blood pressure and puts strain on the heart and kidneys, potentially leading to cardiovascular issues and kidney damage if consumed in excess.
Why Drinking Salt Water Is Harmful
- High Salt Concentration: Seawater contains about 35 grams of salt per liter, while human blood contains about 9 grams per liter. This large difference forces water out of cells to dilute the salt in the bloodstream, causing cellular dehydration.
- Dehydration: Instead of hydrating the body, drinking salt water causes cells to lose water, leading to dehydration symptoms such as thirst, dizziness, headaches, and in severe cases, vomiting and hallucinations.
- Kidney Limitations: Human kidneys cannot make urine saltier than blood, so to eliminate the ingested salt, the body must urinate more water than the amount of salt water consumed. This further promotes dehydration.
- Health Risks: Excess salt intake raises blood pressure, increases the workload on the heart, and can cause kidney damage. It is particularly risky for individuals with hypertension, heart disease, kidney issues, pregnant women, and infants.
Because of these physiological effects, drinking salt water is dangerous and should be avoided.
