Feeling stressed? You're not alone. Stress is an inherent aspect of life in the 21st-century world. Regardless of the cause, stress is bound to affect you at some point during your day or week. And stress can have tremendous negative effects on your mental and physical health. Most Western diseases that slowly get us sick—heart disease, diabetes, stroke—are worsened by stress. Chronic illnesses like rheumatoid arthritis and depression often flare up during repeated instances of stress. This makes coping with stress a critical part of how well we live.