Severe dehydration may trigger kidney injury, say nephrologists

As the dry season approaches, nephrologists have warned that severe dehydration can reduce blood flow to the kidneys and trigger acute kidney injury, urging Nigerians to maintain adequate fluid intake.

The kidney specialists explained that severe dehydration develops when the body loses more fluid than it takes in, especially through excessive heat and sweating, persistent diarrhoea, vomiting or severe bleeding, infections and pregnancy and childbirth complications.

They further noted that although the body has mechanisms to conserve water and signal when fluid levels are low, prolonged or rapid fluid loss could overwhelm these mechanisms and impair kidney function.

The kidney experts advised Nigerians to “obey their thirst” by drinking potable water regularly, avoid indiscriminate use of medicines and seek immediate medical attention when they experience severe vomiting and profuse bleeding, fluid loss or reduced urine output.

In exclusive interviews with PUNCH Healthwise, the nephrologists stressed that acute kidney injury could be reversible when detected early and treated promptly, but warned that delayed treatment could lead to the accumulation of waste products in the body, breathing difficulties, unconsciousness and death.

The experts’ warning comes as Nigeria enters the dry season, with the El Niño weather pattern driving extreme heat and severe public health risks across the country.

El Niño, a climate phenomenon associated with the warming of the tropical Pacific Ocean that can trigger extreme weather conditions, including heatwaves and flooding, could contribute to about 31,400 heat-related deaths between September 2026 and February 2027.

Providing expert insight into the matter, a prominent physician and Consultant Nephrologist, Prof Jacob Awobusuyi, said severe dehydration could affect kidney function by reducing the amount of blood flowing to the organs.

Awobusuyi, a Professor of Medicine at the Lagos State University College of Medicine, Ikeja, and immediate past President of the Nigerian Association of Nephrology, explained that the body continued to lose water through urine, sweating and breathing.

He further noted that severe dehydration could occur when someone was unable to access potable water for several days, especially in extremely hot environments where fluid loss through sweating continued.

Awobusuyi explained that similar injuries could occur when people lost large amounts of fluid through severe diarrhoea and vomiting, including in cholera cases, or experienced substantial blood loss following an accident.

The professor noted that acute kidney injury could also result from other conditions affecting the kidneys, including inflammation and obstruction to the flow of urine.

On warning signs, Awobusuyi said reduced urine output was an important indication that the kidneys might not be functioning properly.

He explained that impaired kidney function could prevent the kidneys from adequately eliminating waste products, causing them to accumulate in the body and affect other organs, including the brain and heart.

Awobusuyi said symptoms of serious kidney injury could develop within three to four days in some cases, especially when a person was no longer producing urine.

The former nephrology association president, however, cautioned against assuming that every reduction in urine output indicated kidney injury, explaining that urine production naturally decreased in hot weather as the body conserved water.

He said urine could become darker and more concentrated when a person sweated heavily, while colder weather could lead to more frequent urination and lighter-coloured urine.

Awobusuyi advised Nigerians to drink water whenever they felt thirsty and take sufficient fluids regularly.

He recommended about two to three litres of water daily for people with normally functioning kidneys, while noting that adequate hydration was essential to replace fluid lost through the kidneys, skin and breathing.

The nephrologist also advised people who engaged in physical activities to replace lost fluids, noting that even swimming could cause water loss.

He cautioned against relying heavily on carbonated and sugary drinks to quench thirst, advising people to minimise their consumption because of their high sugar content.

Also, a Consultant Physician and Nephrologist, Dr Zumnan Gimba, said inadequate water intake could cause the kidneys to malfunction and lead to acute kidney injury, especially when dehydration was severe or occurred rapidly.

Gimba explained that one of the kidneys’ major functions was to maintain the body’s water balance, noting that water made up a substantial proportion of the human body.

The physician said inadequate fluid intake could make it difficult for the kidneys to maintain the body’s water balance and, in severe cases, lead to acute kidney injury.

He, however, explained that acute kidney injury was reversible if detected early and treated promptly, unlike chronic kidney disease, in which kidney damage could be permanent.

Gimba said it was difficult to specify how many days a person could go without water before developing kidney injury because the risk depended on how quickly and severely the person lost fluid.

He identified young children and elderly people as vulnerable groups to kidney problems associated with dehydration.

The nephrologist said thirst was a reliable indication that the body needed more water and advised people not to ignore it.

He added that fluid loss could occur rapidly in people experiencing persistent diarrhoea or vomiting, while those exposed to extreme heat could also lose considerable amounts of water through sweating.

Gimba further identified burns, certain medicines, herbal concoctions, supplements and infections as other possible causes of acute kidney injury, adding that pregnant women experiencing persistent vomiting, pregnancy-related hypertension or severe bleeding during pregnancy or labour are at risk.

The physician explained that severe fluid loss could also cause shock, especially when large amounts of blood or other body fluids were lost within a short period.

Gimba warned that without urgent medical intervention, a person in shock could die.

Gimba advised Nigerians to obey their thirst and increase their fluid intake as the weather became hotter.

He recommended that adults aim for close to three litres of fluids daily, preferably water rather than carbonated or sweetened drinks.

He said the amount should be taken gradually throughout the day rather than all at once, adding that people needed to maintain the habit of drinking sufficient water even when they did not feel thirsty.