How the winter influences our blood pressure

Why blood pressure changes during wintertime

In winter, people are 20 to 50% more likely to die from cardiac, circulatory and vascular diseases than in summer. The possible causes for this are a poor diet, lack of exercise and weaker blood circulation due to the cold temperature. Because high blood pressure (arterial hypertension) is often diagnosed too late, younger and older patients can benefit from regularly having their blood pressure checked during this time of the year. This is particularly important for elderly patients. Their circulatory system reacts more strongly to the cold, resulting in elevated blood pressure. If they already suffer from a pre-existing hypertension and cardiovascular disease, further health risks may arise.

When do we speak of hypertension?

Blood pressure is always measured twofold: the systolic blood pressure, which normally falls between 100 and 129 mmHg, and the diastolic blood pressure, which is the lower pressure in your circulation and falls generally between 60 and 85 mmHg. Numbers that fall within a range of less than 120/80 mmHg are considered normal (optimal) while numbers that exceed the 140/90 range indicate hypertension.

When do we speak of hypertension?

Blood pressure is always measured twofold: the systolic blood pressure, which normally falls between 100 and 129 mmHg, and the diastolic blood pressure, which is the lower pressure in your circulation and falls generally between 60 and 85 mmHg. Numbers that fall within a range of less than 120/80 mmHg are considered normal (optimal) while numbers that exceed the 140/90 range indicate hypertension.

What causes hypertension?

We do not know exactly why our blood pressure rises in winter, but our body’s temperature regulation is significantly involved. When the outside temperature drops, our body prevents heat loss by tightening the smallest skin vessels. In turn, this reduces the blood flow to our extremities and consequently, our blood pressure rises. Fingers and toes can become cold as the blood and heat are redirected to the body’s core and vital organs.

Scientists have also discovered that the concentration of nitrogen monoxide (ON) in our blood decreases during the cold months. ON is a signalling molecule, which is produced in the body and has a vasodilative effect, consequently lowering blood pressure. It activates a signalling cascade to dilate the blood vessels in our body, but at a lower ON concentration. It becomes less effective and the vessel diameter decreases while the pressure rises.

Turning up the heat may be good for your heart

Well-heated rooms may offer a rather unusual method to avoid high blood pressure during the winter months. A Japanese research team discovered that cardiovascular-related mortality is significantly higher in countries with mild winters, than in those which face a harsher climate. Could this be due to a generally higher room temperature? The researchers believes so, as these countries adapt to the cold by using better isolated walls and properly heating up their living spaces. Consequently, the room temperatures are higher on average.

The research team tested their hypothesis and had test subjects sleep in rooms at 14°C and 24°C. In the morning, the team measured the subjects’ blood pressure and found that those who had spent the night in the cold room, displayed a higher blood pressure differing by 5.8 mmHg on average than those who had slept in the warmer room. However, they did not record the effects of a cold night on the test subjects’ blood pressure throughout the rest of the day.

Thoroughly heated flats are neither cost-effective nor eco-friendly and so other measures may prove to be more economical. If you suffer from mild hypertension during the cold winter months, a change in lifestyle could provide relief. Exercising, eating healthy and using table salt more sparingly can have a lasting and positive effect on your blood pressure. But should you suffer from permanent hypertension, drug therapy might be unavoidable.