Loneliness has typically been thought of like most other human emotions — fleeting and virtually harmless. While short periods of loneliness may not have negative effects, prolonged loneliness is toxic and increases the risk of dying by 26%. In fact, loneliness is as harmful to your health as smoking 15 cigarettes a day and increases the risk of heart disease, dementia, depression, stroke, diabetes and cancer. You may be wondering, how can loneliness lead to all ...