Anxiety
Most people experience stress and anxiety at some point in their lives. Generally, stress is usually a response to an external cause, such as a tight deadline at work or having an argument with someone, and usually disappears or reduces once the situation has been resolved.
Anxiety is typically described as a feeling of apprehension or dread in situations where there is no actual real threat and is disproportionate to the situation faced.

Unlike stress, anxiety persists even after a concern has passed. In some cases, anxiety can escalate into an anxiety disorder and can affect day-to-day life.
Credit to Anxiety UK.

