Blood pressure is higher and more difficult to manage in winter, 2023 study shows

How the weather affects blood pressure

Previous studies have shown there is a seasonal variation when it comes to blood pressure.

Generally speaking, blood pressure tends to increase during the cold weather months and decrease during the warmer weather months.

“One of the main ways in which blood pressure gets regulated in the body is the arteries either clamping down or loosening up — we call that vasoconstriction and vasodilation,” explained Dr. Yu-Ming Ni, a board certified cardiologist and lipidologist at MemorialCare Heart and Vascular Institute at Orange Coast Medical Center in Fountain Valley, CA, who was not involved in the recent study.

“If it’s cold outside, you become vasoconstrictive, so the arteries tighten up and the blood pressure goes higher. If you feel hot, then the blood vessels dilate and you get vasodilation that can cool the body down,” Dr. Ni explained for Medical News Today.

A study in April 2021 found that just increasing a room’s temperature by 10 degrees can cause a significant change in systolic blood pressure.

Another study in February 2016 found older adults living in cold homes of less than 64 degrees Fahrenheit had higher blood pressure, poorer biomarkerTrusted Source values in the blood, and worse lung conditions.

Blood pressure in hot vs. cold temperatures

For this study, researchers reviewed electronic health records for over 60,000 adults treated for high blood pressure between July 2018 and June 2023 at six healthcare centers.

Study participants were an average of 62 years old. More than half identified as Caucasian and about 60% identified as female.

When analyzing seasonal blood pressure readings, scientists found that, on average, a study participant’s systolic blood pressure rose by up to 1.7 mm Hg in the winter months compared to the summer months.

Additionally, researchers found that participant blood pressure control rates decreased by up to 5% during the cold weather months.

“The findings supported the existence of seasonal variation in blood pressure, which has been noted in previous studies,” Robert B. Barrett, a software engineer at the American Medical Association in Greenville, SC, and lead author of this study, explained to MNT.

“Despite the smaller degree of systolic blood pressure variation, we were surprised to observe a great degree of change in blood pressure control between winter and summer months. Additionally, [the] temperate season was indicated as a significant predictor of visit control — a feature which has not been extensively described before.”-– Robert B. Barrett, lead study author.

“I have personally seen this effect in my practice quite regularly,” said Nitin Gera, MD, a cardiologist at OhioHealth. “The same patient may have a well-controlled blood pressure when I see them in the summer and then when they come back six months later it can be elevated.”

“In colder months vitamin D levels also decrease which leads to activation of the renin-angiotensin-aldosterone system,” Gera said.

This system regulates blood pressure, fluid and electrolyte balance, and systemic vascular resistance, he explained, which further explains why the cold may cause an increase in blood pressure.

Additionally, lifestyle factors can have an impact on blood pressure, Liu said. People may exercise less or eat a less nutritious diet in winter months, which would both affect blood pressure.

“People tend to eat more in terms of quantity and worse in terms of quality during colder months, especially around the holidays,” Gera said. “I see a bit of a vicious cycle when it is very cold, bleak, and dark where patients feel some degree of seasonal depression and then tend to eat worse and exercise less.”    

Prioritizing Blood Pressure Control During Colder Months

Liu emphasized the importance of monitoring your blood pressure on a regular basis, particularly during the winter months.

Starting with simple, sustainable habits is key. You should exercise consistently, pay close attention to your diet, limit sodium intake, and monitor vitamin D levels, he said.

Gera encourages people to use awareness of seasonal fluctuation in blood pressure to their benefit.

“The way to incorporate this [information] into a treatment plan and hopefully avoid complications is by having heightened vigilance about blood pressure during this period,” he said. “I also recommend anyone with a hypertension diagnosis have a home blood pressure cuff and make sure it is accurate.”

Aside from monitoring blood pressure regularly and reporting changes to your healthcare provider, it’s important to exercise consistently.

“Regular exercise over time causes the release of substances that dilate blood vessels and lower blood pressure,” Gera said.

This is the opposite of what cold weather does to blood vessels—constricts them.1

Managing High Blood Pressure

The Centers for Disease Control and Prevention recommends the following for managing high blood pressure: