Panic attacks typically begin suddenly, without warning. They can strike at any time — when you're driving a car, at the mall, sound asleep or in the middle of a business meeting. You may have occasional panic attacks, or they may occur frequently. Panic attacks have many variations, but symptoms usually peak within minutes. You may feel fatigued and worn out after a panic attack subsides. Panic attacks typically include some of these signs or symptoms: 
Sense of impending doom or danger
Fear of loss of control or death
Rapid, pounding heart rate
Sweating
Trembling or shaking
Shortness of breath or tightness in your throat
Chills
Hot flashes
Nausea
Abdominal cramping
Chest pain
Headache
Dizziness, lightheadedness or faintness
Numbness or tingling sensation
Feeling of unreality or detachment
 One of the worst things about panic attacks is the intense fear that you'll have another one. You may fear having panic attacks so much that you avoid certain situations where they may occur.