Stress- Stress is essentially the feeling of being overwhelmed. Symptoms include difficulty in sleeping, concentration problems, and generalized tension. Stress can result from either internal or external factors, or a combination of both.
Anxiety is a condition of agitation and distress.
The experience of anxiety is fear, but you may not be able to specify what you are fearful about. Anxiety can be experienced in varying degrees of intensity. In its most extreme form, it can cause a person to feel like they are going out of control, or crazy. In a physiological level, anxiety symptoms include rapid heartbeat, muscle tension, queasiness, dry mouth, or sweating. Sometimes a person confuses panic disorder with a heart attack because the symptoms can be similar.