Why kidney disease is rising among outdoor workers

Imagine waking up before sunrise, grabbing a machete, and working all day under the blazing hot sun, just to put food on your family’s table. This is the daily routine for many people in Central America who harvest sugar cane and work on farms. But something strange and serious has happened to these workers: a mysterious kidney disease is making many of them very sick, and scientists are working hard to figure out why.

What is this mysterious kidney disease?

The illness is called chronic kidney disease of unknown cause, or CKDu. Unlike most kidney diseases, which usually affect older people or those with conditions like diabetes or high blood pressure, CKDu mostly strikes healthy young adults, especially men, who work outdoors. In some places, like Bajo Lempa in El Salvador, as many as one in four adult men have kidney disease, which is much higher than the global average. Around 17% of men there live with kidney failure, according to a Nature article exploring this health crisis.

Why are outdoor workers getting sick?

Doctors first noticed something was wrong more than 20 years ago, when young farm workers arrived at hospitals so tired they could barely move. They had none of the usual risk factors for kidney problems. Researchers now believe that working for hours in extreme heat, often without enough water or rest, is a huge part of the problem. Every day, their bodies get overheated and lose water through sweat, forcing their kidneys to work extra hard. Over time, this can cause small injuries to the kidneys that build up until the organs stop working.

How does heat hurt our kidneys?

When we get too hot, our bodies send more blood to the skin to cool down, which means our organs, like the kidneys, get less blood and oxygen. As we sweat to stay cool, we lose even more water. Our kidneys then go into overdrive trying to keep the right balance of fluids, which can stress them out. New research, such as a study in Nicaragua, shows that outdoor workers often have signs of kidney injury during hot harvest seasons. Scientists are also finding early warning signals in the blood and urine that could help spot trouble before it gets worse, as discussed in a recent medical study.

Is heat the only problem?

While heat is a big factor, it might not be the only one. Other possible causes include exposure to harmful chemicals like pesticides or heavy metals, using certain painkillers, or even infections. The cause can vary from place to place. For example, in Sri Lanka, some experts think pesticides may be partly to blame. But heat stress is still the most common link, especially in places where people do heavy work outdoors.

What can be done to protect workers?

The good news is that there are ways to help. Providing more water, giving regular breaks in the shade, and making sure workers don’t have to push themselves in the hottest parts of the day can all lower the risk. Some places are testing new work rules to keep people safe. The World Health Organization has also recognized kidney disease as a major global health problem. And as climate change makes hot days more common, protecting outdoor workers is becoming even more important.

If you want to learn more about how our bodies respond to tough environments, you might enjoy this SlothMD article on muscle power and health, which explains why staying strong helps us face life’s challenges at any age.

Why does this matter for everyone?

CKDu is a warning sign about how our environment and jobs can affect our health. It also shows the importance of catching health problems early, before they become severe. Scientists are now developing new tests and health AI tools to spot kidney problems sooner, so people can get help before it’s too late. You can read more about how science is changing our lives in this SlothMD post about health discoveries and their impact.

The future of kidney health

With more research, better safety rules, and new technology, there is hope for outdoor workers facing dangerous heat. By understanding the science and listening to the stories of people affected, we can work together to protect our kidneys—and our health. Keeping an eye on new studies, like the one discussed in Kidney360, helps us stay prepared as the world changes.