Burnout is a state of emotional, physical, and mental exhaustion caused by excessive and prolonged stress. It occurs when you feel overwhelmed, emotionally drained, and unable to meet constant demands.

According to the World Health Organization (WHO), occupational burnout is a syndrome resulting from chronic work-related stress, with symptoms characterized by "feelings of energy depletion or exhaustion; increased mental distance from one’s job, or feelings of negativism or cynicism related to one's job; and reduced professional efficacy." 

While burnout may influence health and can be a reason for people contacting health services, it is not itself classified by the WHO as a medical condition or mental disorder. The World Health Organization states that "Burn-out refers specifically to phenomena in the occupational context and should not be applied to describe experiences in other areas of life."