What is Anxiety?
Generalized anxiety is very common. Most people experience periods of anxiety in their lives. Others have general anxiety most of the time. The latter condition generally begins between 20-35 years of age, and is somewhat more common in women.

Symptoms
Apprehension
Worry
Dizziness
Sweating
Trembling
Tense feeling
Vigilance
Irritability

Other body systems may be involved, with the resulting possible symptoms:
Headaches, including migraines, Heart racing, Tightness or pressure in the chest, Increased blood pressure, Stomach pain and acid feeling, Indigestion, Hyperventilation or rapid, shallow breathing, Choking sensation, Tingling sensation

Cause
Genetic predisposition, psychological stressors (e.g., social, cultural, and major significant events), neurochemical abnormalities, e.g., serotonin, GABA (gamma aminobutyric acid), and other brain chemicals may all play a role.