People often find that their blood pressure readings tend to rise during winter. Doctors say this is not a coincidence. Cold weather and sudden temperature shifts place real physiological stress on the cardiovascular system, especially in people with hypertension.
According to Dr N Sandeep, Consultant in Cardiology at Manipal Hospitals, Vijayawada, seasonal variation in blood pressure is a well-recognised medical phenomenon, backed by extensive global research.
Why does blood pressure rise in winter
Multiple large studies from Europe, East Asia and India show that systolic blood pressure rises by an average of 5 to 8 mmHg during winter months. The increase is often higher in older adults, people with diabetes, and those with existing heart disease.
The primary reason is how the body reacts to cold. “When the temperature falls, blood vessels constrict in order to conserve body heat,” explains Dr Sandeep. “This makes the vessels narrow, causing the heart to pump harder and blood pressure to rise.” Cold exposure also activates the sympathetic nervous system, which increases stress hormones like noradrenaline. Consequently, heart rate is increased as blood pressure is elevated, especially during the early morning when it is naturally elevated anyway.
The role of blood vessel health
Temperature also has an impact on the inner wall of blood vessels, referred to as the endothelium. For example, in cold temperatures, the body produces reduced levels of a compound called nitric oxide that opens blood vessels.
This leads to the reduced availability of nitric oxide, which translates to poor vessel dilation ability and, therefore, higher blood pressure levels.
Why sudden temperature changes are especially risky
Sudden juxtaposition of a warm inside environment to a cold environment puts tremendous stress on the heart. The body acclimates quickly to the cold, requiring an increased workload. Research suggests that sudden temperature changes can cause sharp spikes of 10 to 20 mmHg in systolic blood pressure, particularly in people with impaired baroreceptor function, the system responsible for sensing and regulating blood pressure changes.
“These rapid fluctuations, when combined with early morning hormonal surges, explain why heart attacks and strokes are more common in winter,” says Dr Sandeep.
Who is most vulnerable?
The following groups are especially vulnerable to cold-induced blood pressure rises:
- Older adults
- People with diabetes or autonomic dysfunction
- Patients with coronary artery disease
- People who have a Weakened Heart
Their bodies are less able to adapt quickly to temperature changes, making even routine cold exposure potentially dangerous.
How to protect your heart in cold weather
Basic and consistent practices to protect yourself from cold:
- Dress warmly, especially during early morning and late evening
- Avoid sudden exposure to cold air
- Remain physically active indoors
- Take regularly prescribed blood pressure medication
- Monitor blood pressure more frequently during winter
In some instances, physicians may adjust the dosage of medication during winter to ensure a controlled level of blood pressure.
Cold weather and unexpected changes in temperature are not only bothersome. They are also independent risk factors for high blood pressure and cardiovascular incidents. It also helps in maintaining the stability of the body temperature, remaining cautious about the blood pressure level, and avoiding sudden exposure to cold temperatures. This can greatly minimise the possibility of complications arising. Therefore, winter care for hypertensives is a necessity.
Disclaimer: Tips and suggestions mentioned in the article are for general information purposes only and should not be construed as professional medical advice. Always consult your doctor or a dietician before starting any fitness programme or making any changes to your diet
