Understanding How Salinity Affects Humans

January 12, 2026 •

3 min read

Nearly 1.89 million deaths each year are associated with consuming too much sodium, a direct consequence of high salinity in diet and drinking water sources. Understanding how salinity affects humans is vital for preventing these severe health issues, particularly for those living in coastal areas or consuming excessive processed foods.

Quick Summary

Excess salinity, particularly from contaminated drinking water, poses severe risks to human health, including hypertension, kidney damage, and dehydration.

Key Points

Hypertension: High salinity, often from drinking contaminated water, causes increased blood pressure by raising blood volume, straining the cardiovascular system.
Kidney Damage: The kidneys work harder to excrete excess salt, which can lead to long-term chronic kidney disease and an impaired ability to regulate fluid balance.
Dehydration: Counterintuitively, excessive salt intake can cause dehydration as the body uses more water to flush out the surplus sodium, leading to intense thirst.
Maternal Risks: Pregnant women consuming high-salinity water face an elevated risk of gestational hypertension and preeclampsia, which can endanger both mother and infant.
Gastrointestinal Distress: High sodium intake, particularly from saline drinking water, can cause acute symptoms such as diarrhea, abdominal pain, and nausea.
Vulnerable Populations: Infants, the elderly, and those with pre-existing health conditions are most susceptible to the adverse effects of high salinity.

The Physiological Effects of High Sodium Intake

Sodium is a vital electrolyte necessary for nerve impulses, muscle function, and maintaining fluid balance. However, consuming excessive amounts, often linked to high-salinity water or processed foods, forces the body's systems into overdrive. The kidneys are primarily responsible for regulating the body's sodium and water balance. When too much sodium is ingested, the body holds onto extra water to maintain a specific sodium-to-water ratio. This increases blood volume, which raises blood pressure and forces the heart to work harder.

Cardiovascular Strain and Long-Term Damage

Chronic high blood pressure is a significant risk factor for cardiovascular disease (CVD), heart attacks, and strokes. Over time, the constant strain from high blood volume causes blood vessel walls to thicken and narrow, further restricting blood flow to critical organs. This reduced blood flow can lead to heart damage or a stroke. Studies in coastal communities exposed to high drinking water salinity have found a strong association with higher rates of hypertension and CVD.

Kidney Strain and Dehydration

To eliminate excess salt, the kidneys require more water. For individuals consuming high-salinity water, this process can lead to severe dehydration. If the sodium level in the blood becomes too high (a condition known as hypernatremia), water is pulled from the body's cells to dilute it, causing cells to shrink. In severe cases, this fluid shift can cause confusion, seizures, coma, or even death. The constant effort to process excess salt can also lead to chronic kidney disease.

Maternal and Infant Health Risks

Pregnant women in coastal regions are particularly vulnerable to the effects of high salinity. Increased consumption of saline drinking water has been linked to higher rates of gestational hypertension and preeclampsia. This can have severe implications for both maternal and infant health, including increased infant mortality rates. A study in Bangladesh showed a significant association between higher saline water consumption during gestation and increased risk of infant death.

The Impact on Vulnerable Populations

Elderly individuals, people with pre-existing heart or kidney conditions, and infants are at the highest risk from high salinity exposure. For example, infants whose formula is mixed with high-saline water are especially susceptible, as their bodies cannot process the excess salt effectively. Similarly, the elderly may have a reduced ability to sense thirst, increasing their risk of dehydration.

Short-Term vs. Long-Term Health Effects


Health Effect	Short-Term Impact	Long-Term Impact
Cardiovascular System	Temporary increase in blood pressure and blood volume.	Chronic high blood pressure, increased risk of heart disease, heart attack, and stroke.
Kidneys	Increased workload to excrete excess sodium, leading to dehydration.	Higher risk of chronic kidney disease and kidney stones.
Body Fluid Balance	Bloating, swelling (edema), and intense thirst.	Cellular shrinkage (hypernatremia) and severe dehydration.
Gastrointestinal System	Nausea, vomiting, abdominal pain, and diarrhea.	Increased risk of stomach cancer.
Musculoskeletal System	Muscle cramps.	Potential for osteoporosis due to calcium excretion.

The Role of Water Sources and Environmental Factors

Salinity intrusion, where saltwater contaminates freshwater sources, is a growing problem in many coastal areas due to climate change, sea-level rise, and human activities like over-extraction of groundwater. Populations relying on these affected water sources are often unknowingly consuming high levels of sodium, a risk that is exacerbated during dry seasons. For instance, studies in Bangladesh have shown significant correlations between high drinking water salinity and increased hospital visits for cardiovascular disease, diarrhea, and abdominal pain.

Coastal communities may also face additional health risks due to a lack of awareness about the dangers of saline water. Women in these regions, who may use saline water for menstrual hygiene due to freshwater scarcity, are at higher risk of reproductive health issues and water-borne diseases. Addressing these environmental and social factors is crucial for mitigating the full spectrum of health problems caused by salinity.

Conclusion: Mitigating Health Risks from Salinity

The impact of salinity on human health is far-reaching, from common issues like dehydration and high blood pressure to more severe and long-term conditions affecting the cardiovascular and renal systems. The problem is particularly acute for coastal communities where freshwater sources are compromised by saltwater intrusion. Mitigation strategies include implementing better water management practices, promoting desalination technologies, and enhancing public awareness campaigns. Ultimately, safeguarding public health requires a multi-pronged approach that addresses both the environmental causes of increasing salinity and the physiological consequences of excessive sodium intake.

Further information on the global impact of climate change on freshwater resources can be found on the Intergovernmental Panel on Climate Change (IPCC) website.

Frequently Asked Questions

Drinking seawater or highly saline water can cause severe dehydration and put a major strain on your kidneys. Your body uses more water to excrete the excess salt than you are consuming, worsening dehydration.

Yes, studies confirm that high drinking water salinity is significantly associated with hypertension (high blood pressure), particularly in coastal populations with high exposure.

Short-term effects include bloating, swelling, and increased thirst. Long-term risks include chronic high blood pressure, kidney disease, and increased risk of stroke and heart attack.

Pregnant women in areas with high water salinity face an increased risk of gestational hypertension and preeclampsia, which can have serious consequences for both maternal and infant health.

Yes, exposure to high levels of saline water has been linked to an increased risk of gastrointestinal issues such as diarrhea, dysentery, and abdominal pain.

Sea salt and table salt have the same sodium content. While sea salt may contain trace minerals, its health effects are largely the same when consumed in excess.

Communities can use rainwater harvesting, desalination technologies like reverse osmosis, and pond sand filter systems. Awareness campaigns and proper water management are also crucial.