context: If you have heart failure, your heart hasn't failed, but it may be weaker than normal. It could be for one of several reasons, like coronary disease or chemotherapy. How does stress affect it? This is still debated, but doctors worry that it could make you sicker. Stress triggers a chemical tsunami in your body. You may have heard it called the âfight or flightâ reaction. Humans could not have survived without such a powerful response to stress. Among other changes, adrenaline and other hormones speed your heart rate and breathing and raise blood sugar levels. This reaction makes your heart require extra oxygen and energy to allow you to, say, run from a tiger. Problem is, the body isn't made to bathe in stress hormones over the long haul. For example, increased stress has been associated with a higher chance of dying. The relationship may be even stronger among people with weakened hearts. Some have argued a relationship between heart failure and a hormone called cortisol, the "stress hormone." One study found that people with heart failure and high levels of cortisol at night had about three times the risk of dying within 18 months as people who had less cortisol. Keep in mind, however, that stress is a complex thing and not entirely understood. Since having a serious medical issue often causes stress, it's not clear which comes first. And some of the effects of it on the heart may have other causes. For example, people who are stressed may not eat healthy, exercise, or take their medications like they are supposed to. These are some of the reasons studies haven't been consistent. For example, a 2014 study found no connection between their stress levels and survival. It cautioned that, even among people without heart failure, âthe overall picture presented by the literature is one of conflicting findings.â Perhaps. It seems to make sense, but studying the relationship is harder than you might think. Relieving stress may help someone feel better, which in turn could make them more apt to follow doctors' orders. But did the improvement come from less stress or better care? We do know that lower stress leads to changes in your body. When stress eases, so do levels of cortisol and adrenaline. This could lessen the burden on your heart. People who took an 8-week course of coping skills and mindfulness that encouraged relaxation and anxiety relief showed improvement over the course of a year, compared with people who did not. This depends on what you find relaxing and mentally soothing, as long as it's not unhealthy things like drinking alcohol or smoking. Meditation, for example, is thought to help the body and mind unwind. One study found that people with heart failure who were taught the principles of meditation said they had better quality of life. It even improved their performance on a 6-minute walk test. Another stress reliever is exercise, which can ease muscle tension and release chemicals in your body that improve your mood. Don't just look to familiar solutions. Tai chi, an ancient Chinese tradition that involves deep breathing coordinated with slow, focused movements, also has some science behind it. Some people hospitalized for heart failure had a drop in stress hormones during a session with a therapy dog. There are lots of ways you can lower your stress. Choose whatever healthy means works for you, whether it's gardening, walking, or finding a few quiet minutes every day for meditation and deep breathing. While the long-term benefit still isn't proven, this much is undisputed: There are no harmful side effects from less stress.