Anxiety disorders generally manifest as distress. Distress generally has three manifestations: 1. Patients have irritability, distraction, feeling inexplicably nervous and worried; 2. Patients have obvious fidgeting, manifesting as inability to sit still, i.e. motor restlessness; 3. Patients are also accompanied by symptoms of autonomic dysfunction, such as panic, palpitations, nausea, regurgitation or symptoms such as bloating and excessive sweating. There are various factors of anxiety disorders, which may be real life stimuli or inexplicable unexplained onset. If a patient experiences anxiety as a result of a stimulus, it is generally called a stress disorder in medical terms. If there is no cause for the onset, it is called generalized anxiety disorder. Severe cases such as sudden onset of paroxysmal panic attacks, palpitations, chest tightness, difficulty in breathing, and in severe cases a sense of near death are called panic attacks.