Burnout is a state of physical, emotional, and mental exhaustion resulting from prolonged stress, most often work-related. Its core features are overwhelming tiredness, feeling detached or cynical about your work, and a sense of reduced effectiveness. People often feel drained, irritable, and unable to cope with demands they once managed easily.
The key difference from depression is that burnout is usually linked to a specific source of stress and may ease when that pressure is reduced or removed, such as taking a break or changing your situation. Depression tends to affect all areas of life, including things unrelated to the stressor, and includes pervasive low mood, loss of pleasure, and sometimes thoughts of worthlessness or self-harm. The two can overlap, and unaddressed burnout can develop into depression.
If rest and reducing stress do not help, or if low mood, hopelessness, or loss of interest spread across your whole life, it is worth seeing a doctor to assess for depression or anxiety. Early support, alongside boundaries and recovery time, helps prevent burnout becoming more serious.