High blood pressure is the leading risk factor for stroke, which can cause paralysis and even be life-threatening. It is considered the most dangerous complication of this condition. So why does high blood pressure lead to stroke, and how can it be prevented?
Why does high blood pressure lead to stroke?
High blood pressure refers to the condition of increased pressure pushing against the walls of the arteries, with a systolic blood pressure reading of 140mmHg and/or a diastolic blood pressure reading of 90mmHg. If not well controlled and persistently elevated over an extended period, high blood pressure can result in heart failure, coronary artery disease, kidney failure, and even stroke.
Stroke, also known as cerebrovascular accident, occurs when the blood vessels supplying the brain become blocked or burst suddenly, causing the patient to experience sensory disturbances and weakness/paralysis on one side of the body. In transient ischemic attacks, the symptoms mentioned above may temporarily diminish within 24 hours. However, in many cases, strokes can lead to persistent symptoms that last for months or even years, causing reduced mobility, loss of work capacity, slurred speech, or the inability to speak, placing significant caregiving burden on families and society.
Compared to individuals with normal blood pressure, hypertensive patients have a significantly higher risk of stroke. The reason high blood pressure leads to stroke is that increased blood pressure places additional strain on the heart and, over time, damages the arteries and various organs in the body. Chronic hypertension leads to the formation of arterial plaques. The rupture of these plaques results in the formation of blood clots or the narrowing and blockage of blood vessels.
Statistics show that 87% of cases where high blood pressure leads to stroke involve narrowed or blocked blood vessels in the brain. This condition reduces blood flow to the brain cells, leading to their death and is referred to as ischemic stroke.
On the other hand, approximately 13% of hypertensive patients experience a stroke due to ruptured blood vessels in or near the brain. This is known as hemorrhagic stroke, as increased blood pressure causes the arteries to bulge and eventually rupture, resulting in bleeding in the brain.
The relationship between high blood pressure and stroke
High blood pressure leading to stroke is no longer a rare condition. In fact, these two health conditions are closely related:
Elevated blood pressure alters the structure of cerebral blood vessels
Increased blood pressure has profound effects on the structure of blood vessels. Specifically:
It promotes the development of atherosclerotic plaques in cerebral arteries and arterioles, which can lead to blockages and local artery damage due to insufficient blood supply. It causes fatty deposits in deep penetrating arteries and arterioles that supply the white matter, resulting in white matter ischemia or cerebral hemorrhage. It induces hypertrophy and remodeling of smooth muscle, leading to narrowing of the lumen. These vascular changes increase blood pressure within the vessels and are considered predictive factors for stroke.
High blood pressure affects cerebral blood flow
In patients with hypertension, cerebral autoregulation is impaired, resulting in decreased cerebral blood flow, especially in regions with high perfusion pressure over an extended period. This condition leads to white matter damage. Additionally, high blood pressure can disrupt the endothelial function of cerebral blood vessels, increase blood-brain barrier permeability, and result in cerebral edema.
Hypertension induces oxidative stress on cerebral blood vessels
When the antioxidant defense system becomes overwhelmed, oxidative stress occurs. This leads to a depletion of antioxidant molecules and loss of antioxidant activity. Paradoxically, oxidative stress plays a significant role in the pathogenesis of hypertension and, if prolonged, can contribute to stroke.
High blood pressure and dysregulated arterial tone
Arterial tone regulation is one of the crucial physiological reflexes involved in blood pressure regulation. Impaired arterial tone regulation makes the vessels more prone to atherosclerosis and less responsive to blood pressure changes. Thus, the regulation of arterial tone plays a crucial role in hypertension and its associated complications.
How is high blood pressure-related stroke managed?
High blood pressure can lead to a stroke with potentially dangerous complications if not detected and treated promptly. Therefore, when stroke symptoms are recognized, both the patient and caregivers need to take immediate first aid measures and implement supportive actions to prevent complications.
If it is a transient stroke, there is no need to be overly concerned as the symptoms may disappear within 24 hours. However, if the patient experiences loss of consciousness, sensory or motor deficits, it is an actual stroke and requires medical care. At this point, emergency medical services should be called to transport the patient to the hospital.
While waiting for medical assistance, the following measures should be taken:
- If the patient is unconscious, it implies compromised respiratory function, and any saliva or phlegm produced cannot be swallowed down the esophagus. The patient should be positioned on their side to prevent the regurgitation of saliva or phlegm into the airway, which can lead to airway obstruction and respiratory arrest.
- Do not move the patient or attempt to make them stand up.
- Loosen tight clothing and remove the chest strap to allow for relaxed breathing. Avoid overcrowding the area, as it can deprive the patient of oxygen.
- Absolutely refrain from applying oils, scraping the skin, applying lime to the soles of the feet, or pricking the fingertips, as these not only have no efficacy but can also cause harm and inadvertently increase blood pressure.
- DO NOT allow the patient to eat, drink, or take medication, as this can easily lead to airway obstruction and dangerous situations.
It is crucial to take advantage of the golden 3-hour window for emergency treatment after a stroke to eliminate complications and preserve the patient’s life. Delayed hospital admission can hinder the recovery of brain cells and normal cells alike. This can result in lifelong disabilities, inability to speak, loss of self-care abilities, and even death within a few days.
Preventing Stroke Due to High Blood Pressure
In patients with high blood pressure, the risk of stroke is significantly increased without proper care and moderation in lifestyle. Therefore, to prevent high blood pressure from leading to a stroke, individuals should take the following measures:
- Limit consumption of salt and avoid processed foods, canned goods, fast food, etc., as these are high-sodium foods that can elevate blood pressure and have negative effects on health. Increase intake of green vegetables and foods rich in vitamins in daily meals.
- Drink an adequate amount of water, at least 2 liters per day, to ensure hydration for bodily functions.
- Engage in moderate physical exercise or sports, aiming for 30-60 minutes per day, to improve overall health and ward off diseases.
- Undergo regular health check-ups and proactively monitor blood pressure readings and disease progression to intervene promptly.
High blood pressure leading to stroke is an extremely dangerous complication that can claim the patient’s life. Therefore, if someone is suffering from high blood pressure, it is crucial to actively monitor their health, take note of symptoms, and promptly seek medical advice. Avoid being complacent or underestimating the warning signs of stroke due to high blood pressure, as they can result in regrettable consequences.
John Alen was born in 1971 and is a doctor in the healthcare and psychology fields with many years of experience. He is currently working at easyhealthylive.com, a leading health and psychology blog. Having studied at Y1 National Medical University named after IM Sechenov, John Alen is using his knowledge and experience to help improve the physical and mental health of people in the United States.