Why Does Hot Weather Increase the Risk of Stroke?

Hot weather is a "catalyst" for strokes. Medical research shows that high temperatures can lead to excessive sweating, blood concentration, increased blood pressure fluctuations, and even trigger dehydration and electrolyte imbalances, all of which are key conditions for the formation of strokes.

In high-temperature environments, the body sweats profusely to dissipate heat, losing not only water but also important electrolytes like sodium and potassium. Blood viscosity increases, blood flow slows, and platelet activity enhances, making it easy to form blood clots in the blood vessels. Once these clots block the arteries in the brain, it can lead to a stroke.

Professor Li, head of the neurology department at Beijing Xuanwu Hospital, pointed out: "The incidence of strokes in summer is not less than in winter; in fact, elderly people may become more careless in summer, neglecting hydration, which is even more dangerous."

Moreover, sustained high temperatures at night can disrupt sleep, leading to increased sympathetic nervous system activity and blood pressure fluctuations. These combined factors make individuals with already fragile blood vessels and atherosclerosis more susceptible to a fatal blow in summer.

Skipping Breakfast: The Hidden Minefield in the Morning

The plan for the day starts in the morning, yet many office workers and elderly people choose to skip breakfast due to the heat or lack of appetite. While it seems like a time-saver, it is actually the first "trigger" for stroke risk.

In a fasting state, the body's blood sugar level is low, leading to increased sympathetic nervous system activity and a faster heart rate, while also promoting blood concentration and elevated blood pressure. Especially in the morning, which is already a peak time for cardiovascular events, the absence of breakfast combined with high-temperature stimuli may be the "last straw" that triggers a stroke.

Mr. Chen, a 65-year-old retired teacher from Jiaxing, Zhejiang, who has always valued health, often skips breakfast due to fear of heat. One morning, after exercising and returning home, he suddenly felt his mouth drooping and his speech was unclear. He was urgently sent to the hospital and diagnosed with an acute stroke. Doctors determined that his condition was closely related to the combination of "waking up on an empty stomach, high temperatures, and dehydration."

Recommendation: Even if you lack appetite, you should still consume some nutrition, such as a cup of warm soy milk with whole grain bread or an egg, to prevent low blood sugar and blood viscosity. This is especially important for the elderly and those with chronic diseases, who should never neglect breakfast.

Summer Naps: Napping on the Sofa Can Be Dangerous

In the scorching summer, many people like to "catch up on sleep" in the afternoon, but improper napping methods can become an "invisible trap" that triggers strokes.

Clinically, cases of strokes occurring after napping are not uncommon, mainly due to improper body position during the nap leading to poor blood flow; direct air conditioning blowing on the neck causing blood vessels to constrict; and sudden standing up after waking causing severe blood pressure fluctuations.

A retired official, Aunt Xu (63 years old) from Fuzhou, Fujian, has a habit of napping on her side on the sofa. One afternoon, after waking up, she suddenly felt weakness in her right hand and spoke unclearly. Her family rushed her to the hospital, where she was diagnosed with a mild stroke. Doctors indicated that lying on her side compressed the carotid artery, combined with direct air conditioning, was one of the triggers.

The correct way to nap is to lie on your back, avoiding excessive head turning or pressure; keep the air conditioning temperature between 26-28°C, and do not let it blow directly on the head and neck. After waking up, rise slowly to avoid sudden changes in blood pressure.

Not Hydrating: Blood Concentration Triggers the "Silent Killer"

"Drink more water when it's hot" is a saying everyone has heard, but not everyone truly follows it. Especially for some elderly people, the sense of thirst diminishes, and if they don't feel thirsty, they won't drink, resulting in less than 500ml of water intake in a day, which actually puts them in a state of mild dehydration.

In medicine, strokes caused by dehydration are referred to as "dehydration-type strokes." These patients often have no obvious triggers and may suddenly fall ill in high temperatures, feeling fatigued, and not hydrating in time. Due to atypical symptoms, diagnosis and treatment can be easily delayed.

Mr. Gao, a 72-year-old hypertensive patient from Shijiazhuang, Hebei, did not drink water for almost an entire day due to fear of needing to use the restroom while out in the city. After returning home, he experienced symptoms such as blurred vision and weakness on one side, and was diagnosed with a moderate stroke.

Doctors pointed out that especially in hot weather, the body's daily basic water loss can reach 1500-2000ml, and if there is not enough water intake at this time, the blood will become abnormally concentrated, thereby increasing the risk of thrombosis.

Recommendation: Do not wait until you are thirsty to drink water; you should actively hydrate, especially in the morning after waking up, after exercising, before meals, and in the afternoon. It is recommended to drink small amounts multiple times, about 150-200ml each time, to avoid the burden of drinking a large amount of water at once on the heart and kidneys.

Why Do Doctors Say "It's Better to Play Mahjong Than to Do These Three Things"?

This seemingly humorous metaphor actually carries rich clinical experience and observation. While playing mahjong also involves prolonged sitting, it has several advantages compared to the three major behaviors of "fasting, improper napping, and not hydrating":

It is usually conducted in a well-ventilated air-conditioned environment;

It involves communication and thinking, providing some mental activity;

Most people will drink tea or water while playing mahjong, inadvertently maintaining their fluid intake.

Dr. Xie, head of the cardiology department at a top-tier hospital in Guangdong, stated: "We are not encouraging everyone to become addicted to mahjong, but we want to emphasize that if life behaviors in high temperatures are chosen wisely, risks can be completely avoided. The combination of socializing and calm activities like playing mahjong can actually be beneficial for the elderly."

Of course, mahjong sessions should not be too long to avoid staying up late; sitting posture should be comfortable, and the environment should be quiet and at a constant temperature; more importantly, it is essential to get up and move around at appropriate times to prevent venous thrombosis.

Who Are the Key Groups to Prevent Stroke in Summer?

Not everyone faces the same risk. The following groups should be particularly vigilant about the occurrence of strokes during the hot season:

Patients with hypertension, diabetes, and high cholesterol: These chronic diseases are the underlying conditions for strokes;

Rehabilitators with a history of strokes: Once triggers are reactivated, the probability of recurrence is very high;

Individuals with poor lifestyle habits such as smoking, excessive drinking, and staying up late: Their vascular conditions are unstable, making them prone to sudden events;

The elderly: With decreased vascular elasticity and weakened self-regulation ability, their risk doubles;

Patients on long-term diuretics and antihypertensive medications: They need to pay more attention to hydration and blood pressure monitoring.

These groups should regularly monitor blood pressure, blood sugar, and blood lipids in summer, while also adjusting their daily routines and dietary habits. Families should keep routine emergency medications, such as aspirin and nitroglycerin, on hand and ensure clear communication and access to medical care.