Anxiety disorders include general anxiety disorder, post-traumatic stress disorder and phobias. Characterized by constant fearfulness and worry, anxiety disorders can be long-term problems requiring psychiatric medication or therapy. Though the exact cause of anxiety is still being researched, several factors are believed to contribute to anxiety, including neurotransmitters, stress and genetics.
Neurotransmitters
Chemicals in the brain called neurotransmitters relay electrical signals between neurons, which deliver messages from your brain to your body. An imbalance in neurotransmitters--specifically serotonin, dopamine and norepinephrine, according to the Mayo Clinic--is believed to effect the occurrence of anxiety. Proper levels of serotonin are needed to maintain a balanced mood. When serotonin levels are inadequate, moods may fluctuate or symptoms of anxiety may surface. Dopamine influences motivation and focus. Low dopamine levels may cause depression, while high dopamine levels may cause anxiety. Norepinephrine influences the stimulation of the body. Increased amounts of norepinephrine result in overstimulation and may cause anxiety.
Stress
The stress response, your body's natural response to a threat, helps you stay focused and alert. In small doses this response is helpful, protecting you from harm and motivating you to do your best in the face of a challenge. Too much stress, however, damages your mood, relationships and quality of life. When stress becomes chronic, The New York Times Health Guide reports, it may lead to anxiety and result in constant fearfulness, irritability and sleeplessness.
Genetics
Genetics is thought to play a role in the development of anxiety disorders. However, genes alone cannot determine who will and who will not suffer from an anxiety disorder. Rather, genetics in combination with experiences influence the development of anxiety. Genetics may help explain why when two people are exposed to the same event or situation, one develops symptoms of anxiety and the other does not.
