Heart disease is the leading cause of death globally, but there is another fact that not many people know about it. Heart attacks have their own cycle or pattern, and that depends on the time of day.

Studies have shown that there are certain times of the day when the risk of heart attack is higher. Researchers believe that this cyclical pattern may have something to do with our body’s internal clock, which affects our metabolism, stress response, and blood pressure levels over the course of the day.

Timing Matters for the Heart

The heart is not equally vulnerable to heart attack throughout the day. The risk of heart attack is highest in the morning, specifically between 6 a.m. and 12 p.m. The risk dips during the afternoon, and it rises again in the early evening, between 6 p.m.

and midnight. This cycle is not limited to individuals with pre-existing cardiovascular disease; it can also apply to healthy people.

The daily variation in heart attack risk might have to do with the body’s circadian rhythm. This internal clock determines the body’s sleep-wake cycles, but it also impacts the cardiovascular system, endocrine system, and other functions.

This rhythm is driven by a complex interplay of genes, proteins, and hormones that regulate different bodily processes, including blood pressure, heart rate, and inflammation.

Heart Attacks and the Morning Surge

The morning surge in heart attack risk is something that scientists have been studying for decades.

Based on a review of studies, the American Heart Association found that the risk of heart attack increased by 40 percent in the morning compared to other times of the day. The cause of this phenomenon is not entirely clear, but there are a few potential explanations.

One possibility is that the body’s hormonal fluctuations in the morning could trigger a series of events that lead to the formation of blood clots or cardiac arrhythmias, which in turn could cause a heart attack.

For example, cortisol, a stress hormone, rises in the morning, which could increase blood pressure and heart rate, and make blood vessels constrict. Another theory is that the sudden switch from the parasympathetic (rest and digest) to the sympathetic (fight or flight) nervous system in the morning could cause stress on the heart and the blood vessels.

The morning surge in heart attacks could also be related to disruptions in sleep, which often occur in people with sleep apnea or insomnia.

The Afternoon Lull and the Evening Spike

After the morning peak, the risk of heart attack drops significantly in the afternoon, especially between 12 p.m. and 6 p.m.

This is known as the “siesta” period, and it might be due to the body’s natural tendency to lower blood pressure and heart rate during this time. However, the risk of heart attack picks up again in the early evening, between 6 p.m. and midnight. This cycle is less studied than the morning peak, but there are some hypotheses.

One possibility is that the evening spike is related to the body’s response to stress when people return home from work.

Stress is a known risk factor for heart attack, and when people experience a sudden increase in stress levels, such as from traffic, arguments, or financial worries, it could trigger a cascade of physiological reactions that increase the risk of heart attack. Another theory is that the evening spike is related to variations in blood pressure, which tend to be higher in the evening than in the morning. This could increase the strain on the heart and make it more vulnerable to damage.

What Can You Do to Lower Your Risk?

While you can’t change the fact that the risk of heart attack varies over the course of the day, there are some steps you can take to mitigate your risk.

Manage Your Stress

Since stress is a significant risk factor for heart attack, finding healthy ways to cope with stress can be beneficial.

That could mean practicing relaxation techniques, such as deep breathing, yoga, or mindfulness meditation, or seeking the support of a mental health professional if you have unresolved stress or anxiety. Exercise is another potent stress reliever that can also improve cardiovascular health.

Get Enough Sleep

Disruptions in sleep can affect the body’s circadian rhythm and lead to higher heart attack risk.

To promote healthy sleep, aim for at least seven hours of sleep per night, avoid caffeine, alcohol, and nicotine before bedtime, and maintain a consistent sleep schedule. If you have sleep apnea or other sleep disorders, seek treatment.

Exercise Regularly

Exercise is one of the most effective ways to reduce heart attack risk. Regular physical activity not only strengthens the heart and circulatory system but also lowers blood pressure, cholesterol, and body weight.

Aim for at least 30 minutes of moderate-intensity exercise most days of the week, such as brisk walking, cycling, or dancing.

Eat a Healthy Diet

Your diet can play a significant role in heart health. Aim for a balanced diet that’s rich in fruits, vegetables, whole grains, lean protein, and healthy fats such as nuts and olive oil.

Limit your intake of processed and fried foods, red meat, sugary drinks, and foods high in sodium, saturated fat, and cholesterol.

Conclusion

Heart attack risk varies throughout the day, with the highest risk in the morning, a mid-afternoon lull, and a rising risk in the early evening.

While the reasons for this cyclical pattern are not entirely clear, researchers believe that the body’s circadian rhythm and hormonal fluctuations could play a role. To lower your risk of heart attack, you should manage your stress, get enough sleep, exercise regularly, and eat a healthy diet. By taking these steps, you can protect your heart and reduce your chances of heart disease.