By Naomi D. L. Fisher, M.D.
Harvard Health Blog
Stress is rampant, and high blood pressure (what doctors call hypertension) is on the rise. So it’s no wonder patients often ask if stress is causing their hypertension. We have no proof that stress alone can cause persistently elevated blood pressure. (Part of the reason is that high-quality studies quantifying stress are difficult to conduct.) But stress can certainly raise blood pressure, sometimes impressively. And stress reduction can lower blood pressure, frequently improving overall well-being. Deep, slow breathing is the oldest and best-known technique to decrease stress.
The relationship between stress and blood pressure
Blood pressure regulation is highly dynamic, responding to many interacting factors, ranging from alcohol and sodium intake to sleep and hormone levels. Stress is a key player, with all sorts of stressors (on the job, at home, in the classroom) contributing to a rise in blood pressure. Stress revs up the autonomic nervous system. This system oversees processes generally not under conscious control, including blood pressure and heart rate, but also more mundane functions like sweating and flushing. The hormone adrenaline is a fundamental part of its response.
For much of human evolution, increased nervous system activity has been protective, preparing us to “fight or flight” in a crisis. But today this response is rarely needed, and can even be maladaptive. Most people exhibit some instinctive reactivity: for example, if you’ve ever heard a police siren while driving, you probably noticed a jump in heart rate. There is tremendous variability in how people respond to stress, however. Many people have a highly reactive system. Their nerves and stress hormones can fire in low-pressure situations, like waiting in line or losing a button — and this isn’t always associated with a noticeable feeling of anxiety. Sometimes the nervous system even responds to worried thoughts alone.
Getting a handle on the stress response
Luckily, you can manage that stress response. Common prescriptions include exercise, laughter, and a good night’s sleep. We can also interrupt the acute response to stress by reconditioning our reactions to its triggers.
Simply taking a deep breath is one way to start. A focus on breathing lies at the core of various relaxation techniques. Yogis have incorporated slow breathing as part of meditation practices for centuries, and in the 1970s, the medical world formalized this connection when Dr. Herbert Benson first described the “relaxation response.”
Many of us recognize the value of “taking a deep breath” in everyday situations. Doctors often ask patients to breathe deeply before getting their blood pressure taken, for example, and mindful people may take a deep breath before responding to an insult. But it is also helpful to incorporate deep breathing in a daily routine, especially for “type A” or stress-prone personalities, with an added benefit on blood pressure.
How to get started with deep breathing
One beginner method is called equal breathing, based on inhaling through the nose for a count of four, and exhaling for a count of four. With time, this cycle can be prolonged to counts of eight in, eight out. Another method, called guided visualization, encourages users to hold on to mental images of a peaceful place as they breathe deeply.
There is only one non-drug treatment approved for hypertension by the FDA — a device called RESPeRATE. It uses musical tones to guide deep abdominal breathing. Its goal is to reduce the number of breaths to under 10 per minute, and to prolong each exhalation. Clinical trials have shown that daily RESPeRATE use lowered blood pressure, sometimes as much as a blood pressure pill would have. This lowering effect also lasted long after each session. Instead of a RESPeRATE device, you can always use one of several free mobile apps that teach deep breathing.
Deep breathing shouldn’t replace blood pressure medications, but it can be a helpful supplement. Its advantages are obvious: it is free, portable, and healthful. The only cost is time — ideally, 10 to 15 minutes daily. Adding guided breathing to your routine is a great way to lower your blood pressure while helping you handle the ever-growing stresses of modern life.
(Naomi D. L. Fisher, M.D., is a contributor to Harvard Health Publications.)