Do panic attacks just come out of nowhere?

Expected panic attacks are typically associated with a specific trigger such as crowds, flying or exams, whereas unexpected panic attacks have no apparent trigger and can seem to happen for no reason. It is not yet known what causes panic attacks but certain factors may play an important role, including genetics, mental health conditions, major stress or having a predisposition to stress.Panic attacks are typically experienced as a result of misinterpreting physical symptoms of anxiety. Heart palpitations may be mistaken for symptoms of a heart attack, breathlessness or feeling faint may be taken as a sign that a person is collapsing or dying, and the racing thoughts can lead a person to think that they are losing control of their mind. These misinterpretations – which a person may be unaware that they are doing – can trigger a panic attack, which seems to appear out of the blue.