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Dramatic temperature changes linked to half a million stroke deaths

A recent study has revealed a potential link between climate change and an increase in stroke-related deaths and disabilities worldwide. Over a span of three decades, researchers observed a rising correlation between non-optimal temperatures (both higher and lower than those associated with the lowest mortality rates) and stroke incidences. 

It’s crucial to note, however, that the study establishes a correlation rather than causation between climate variability and stroke risk, and does not account for other stroke risk factors like hypertension and high cholesterol.

Dramatic temperature changes and human health 

The experts found that strokes associated with colder temperatures, which can lead to blood vessel constriction and elevated blood pressure – a known stroke risk factor – comprised the majority of cases. 

Nonetheless, an uptick in strokes related to warmer temperatures was also observed. Heat can lead to dehydration, potentially affecting cholesterol levels and slowing blood flow, both of which are conducive to stroke.

“Dramatic temperature changes in recent years have affected human health and caused widespread concern,” said lead author Quan Cheng, an expert in neurosurgery at the Xiangya Hospital Central South University in Changsha, China

“Our study found that these changing temperatures may increase the burden of stroke worldwide, especially in older populations and areas with more health care disparities.”

This comprehensive study analyzed three decades of health data from over 200 countries and territories, focusing on stroke mortality and the burden of stroke-related disability attributable to non-optimal temperatures. The researchers then classified the data by region, country, and demographic groups, including age and gender.

In 2019 alone, non-optimal temperatures were linked to 521,031 stroke deaths and 9.4 million disability-adjusted life years – a metric that combines years lost due to premature death and years lived with disability – attributable to stroke. A significant portion of these deaths, 474,002 to be exact, were associated with lower temperatures.

Impact of temperature change on stroke 

The researchers also revealed gender disparities in temperature-related stroke mortality rates, with males experiencing a higher rate (7.7 per 100,000) than females (5.9 per 100,000). Geographically, Central Asia reported the highest stroke death rate due to non-optimal temperatures, at 18 per 100,000, with North Macedonia registering the highest national rate at 33 per 100,000.

“More research is needed to determine the impact of temperature change on stroke and to target solutions to address health inequalities. Future research should aim to reduce this threat by finding effective health policies that address potential causes of climate change, such as the burning of fossil fuels, deforestation and industrial processes,” Cheng concluded.

More about strokes

Strokes are a medical condition that occur when the blood supply to part of the brain is reduced or interrupted, preventing brain tissue from getting oxygen and nutrients. Brain cells begin to die within minutes. This condition is a major cause of disability and can be fatal in severe cases. 

Types of stroke

There are two main types of strokes: ischemic, caused by blocked arteries leading to the brain, and hemorrhagic, caused by bleeding into brain tissue. A third condition, known as a transient ischemic attack (TIA), or “mini-stroke,” involves a temporary disruption of blood flow to the brain, often serving as a warning sign for a future stroke.

FAST symptoms

The symptoms of a stroke can be remembered by the acronym FAST: Face drooping, Arm weakness, Speech difficulties, and Time to call emergency services if these symptoms are observed. Quick action is critical to minimize brain damage and potential complications.

Risk factors

Risk factors for stroke include high blood pressure, smoking, diabetes, high cholesterol levels, sedentary lifestyle, obesity, and certain genetic factors. Preventative measures focus on controlling these risk factors through lifestyle changes and, in some cases, medications.


Treatment for stroke depends on the type. For ischemic strokes, medications to dissolve clots and prevent new ones from forming are commonly used. Hemorrhagic strokes may require surgery to repair damaged blood vessels or reduce pressure within the brain.

Recovery varies widely among stroke survivors. Some people recover completely, but more than two-thirds of survivors will have some type of disability. Rehabilitation programs that include physical therapy, speech therapy, and occupational therapy play a crucial role in recovery, aiming to help individuals regain as much independence as possible.

Stroke prevention 

Research into stroke prevention and treatment is ongoing, focusing on better ways to protect the brain from damage, enhance recovery, and prevent recurrences. Innovations in medical technology, such as clot retrieval devices and advanced imaging techniques, have significantly improved outcomes for stroke patients in recent years.

The study is published in the journal Neurology®.


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