A significant rise in stroke cases is observed during the month of July. A large study conducted in China, which analyzed over 82,000 cases between 2019 and 2021, recorded nearly a doubling of the risk of ischemic stroke on days when temperatures reached or exceeded 33°C. This particular research demonstrated how heatstroke and dehydration conditions—common in July—increase blood viscosity, while at the same time potentially blocking cerebral blood vessels. In short, these conditions strongly favor the occurrence of strokes.
According to the findings, the onset of such events peaks within the first 10 hours of exposure to extreme heat, confirming that the effect of high temperatures is not theoretical but immediate and potentially fatal, reports iatropedia.gr.
**Strokes: The Biological Mechanism Behind the Risk**
The biological mechanisms behind this phenomenon are clear. Excessive sweating and dehydration caused by heat increase blood coagulation, creating a favorable environment for clot formation. At the same time, the cardiovascular system becomes overloaded due to thermoregulation via vasodilation and tachycardia, which can disrupt arterial pressure.
The World Health Organization (WHO) has confirmed that sudden temperature spikes immediately increase cardiovascular and renal disease rates on the same or following days.
**The Role of Dehydration, Hypertension, and Heatstroke**
Dehydration, hypertension, and heatstroke form an absolute ‘explosive mix.’ Specifically, the factors that lead to increased vascular stroke incidents during July include:
– **Dehydration**: Exposure to high temperatures causes excessive sweating and fluid/electrolyte loss, increasing blood viscosity. Dr. John Neel, Professor at the University of San Diego, emphasizes that this process leads to fatigue, dizziness, headaches, and reduced blood flow—all precursors to a stroke.
– **Increased Blood Pressure & Cardiac Strain**: The body generates contractions to cool itself, directing blood toward the skin while exerting pressure on organs. Both heart rate and blood pressure increase simultaneously.
– **Heatstroke**: When the body overheats—above 40°C—confusion, seizures, and neurological symptoms like hemiplegia appear. However, caution is needed, as these are common signs of both heatstroke and stroke.
**SOS Signs: How to Recognize That Something Is Wrong**
The basic symptoms of a stroke, especially during heatwaves, require immediate action. The symptoms you should be concerned about include:
– Weakness/numbness (often in the arm or leg)
– Difficulty walking, instability, or dizziness
– Numbness on one side of the body
– Blurred or double vision
– Sudden or severe headache
– Difficulty speaking or confusion
At the same time, there may also be symptoms of dehydration or heatstroke, such as:
– Dry mouth, no urination for hours
– Severe dizziness, nausea, or vomiting
– High body temperature
– Confusion and loss of consciousness
**Prevention Saves Lives**
As the WHO notes, it’s not just the heat itself but the explosive pathophysiological chain reaction it triggers, often leading to hospitalization. Heatwaves significantly worsen cardiovascular, respiratory, and kidney diseases, with emergency admissions rising on the same or next day.
Special attention is required for the elderly and those with chronic illnesses (such as hypertension, diabetes, etc.). Doctors emphasize that as soon as the first alarming symptoms appear, do not wait—call emergency services and transport the patient to the hospital immediately.