Whether it’s a simple spat with your spouse or long-held resentment toward a family member or friend, unresolved conflict can go deeper than you may realize—it may be affecting your physical health. The good news: Studies have found that the act of forgiveness can reap huge rewards for your health, lowering the risk of heart attack; improving cholesterol levels and sleep; and reducing pain, blood pressure, and levels of anxiety, depression and stress. And research points to an increase in the forgiveness-health connection as you age. . . . Chronic anger puts you into a fight-or-flight mode, which results in numerous changes in heart rate, blood pressure and immune response. Those changes, then, increase the risk of depression, heart disease and diabetes, among other conditions. Forgiveness, however, calms stress levels, leading to improved health.