It is normal to experience occasional anxiety, which can manifest as tension, worry, uneasiness, and apprehension.  But an anxiety disorder is characterized by pervasive anxiety and can disrupt your life and your health. There are many types of anxiety disorders, which can sometimes be crippling conditions that cause intense emotional and physical reactions.

According to the National Institute of Mental Health, anxiety disorders are among the most common mental disorders in the United States, affecting 18% of the adult population and 25% of teenagers in any given year. Most anxiety disorders get better with a combination of medication, therapy, and counseling.  Some people also benefit from lifestyle changes.

Anxiety disorder is an umbrella term that covers several common psychiatric disorders; while each has different symptoms, all involve excessive nervousness or fear about future uncertainties based on real or imagined events. To qualify as an anxiety disorder, the anxiety needs to interfere with day-to-day living for a period of six months or longer.

The American Psychological Association recognizes several types of anxiety disorders:

A panic attack is a sudden bout of intense distress. Your heart may beat quickly, or you may have trouble breathing. Panic attacks often cause chest pains or feelings of being choked or smothered. If you suffer regularly from panic attacks, you may be diagnosed with panic disorder.

 A phobia is an irrational fear. It may be a fear of something specific, such as spiders, bats, or the dark. Or it may be more general, such as social phobia, in which social or performance situations make you nervous and you try to avoid them.

If you have obsessive-compulsive disorder, you may have trouble getting your mind off certain things. You may have a worry that doesn’t go away, or an overwhelming feeling that you must regularly perform a seemingly meaningless task, such as repeated hand washing or counting the same coins over and over again.

 Post-traumatic stress disorder (PTSD) and acute stress disorder can make it very hard to move forward after experiencing a traumatic event—causing you to relive that experience over and over.

Generalized anxiety disorder is a feeling of constant worry or nervousness about life in general.

Severe anxiety may also be a symptom of some other illness, such as drug or alcohol abuse, thyroid problems, or depression.