Everyone experiences anxiety. However, when feelings of intense fear and distress are overwhelming and prevent us from doing everyday things, an anxiety disorder may be the cause. Anxiety disorders are the most common mental health concern in the United States. An estimated 40 million adults in the U.S., or 18%, have an anxiety disorder. Approximately 8% of children and teenagers experience the negative impact of an anxiety disorder at school and at home.

What is normal anxiety?
A certain amount of anxiety is normal and necessary; it can lead you to act on your concerns and protect you from harm. In some situations, anxiety can even be essential to your survival. If you were standing at the edge of a curb, for example, and a car swerved toward you, you would immediately perceive danger, feel alarm and jump back to avoid the car. This normal anxiety response, called the “fight or flight” response, is what prompts you to either fight or flee from danger.
When we feel danger, or think that danger is about to occur, the brain sends a message to the nervous system, which responds by releasing adrenaline. Increased adrenaline causes us to feel alert and energetic, and gives us a spurt of strength, preparing us to attack (fight) or escape to safety (flight). Increased adrenaline can also have unpleasant side-effects. These can include feeling nervous, tense, dizzy, sweaty, shaky or breathless. Such effects can be disturbing, but they are not harmful to the body and generally do not last long.
Symptoms
Just like with any mental illness, people with anxiety disorders experience symptoms differently. But for most people, anxiety changes how they function day-to-day. People can experience one or more of the following symptoms:
Emotional symptoms:
• Feelings of apprehension or dread
• Feeling tense and jumpy
• Restlessness or irritability
•Anticipating the worst and being watchful for signs of danger
Physical symptoms:
• Pounding or racing heart and shortness of breath
• Upset stomach
• Sweating, tremors and twitches
• Headaches, fatigue and insomnia
• Upset stomach, frequent urination or diarrhea
How does anxiety affect us?
Whenever the fight or flight response is activated by danger, either real or imagined, it leads to changes in three “systems of functioning”: the way you think (cognitive), the way your body feels and works (physical), and the way you act (behavioural). How much these three systems change varies, depending on the person and the context.
1. Cognitive: Attention shifts immediately and automatically to the potential threat. The effect on a person’s thinking can range from mild worry to extreme terror.
2. Physical: Effects include heart palpitations or increased heart rate, shallow breathing, trembling or shaking, sweating, dizziness or lightheadedness, feeling “weak in the knees,” freezing, muscle tension, shortness of breath and nausea.
3. Behavioural: People engage in certain behaviours and refrain from others as a way to protect themselves from anxiety (e.g., taking self-defence classes or avoiding certain streets after dark).
Diagnosis
The physical symptoms of an anxiety disorder can be easily confused with other medical conditions like heart disease or hyperthyroidism. Therefore, a doctor will likely perform a carefully evaluate involving a physical examination, an interview and ordering lab tests. After ruling out a medical illness, the doctor may recommend a person see a mental health professional to make a diagnosis.
Treatment
As each anxiety disorder has a different set of symptoms, the types of treatment that a mental health professional may suggest also can vary. But there are common types of treatment that are used:
• Psychotherapy, including cognitive behavioral therapy (CBT)
• Medications, including anti-anxiety medications and antidepressants
• Complementary health approaches, including stress and relaxation techniques.
What are anxiety disorders?
Anxiety can be experienced in lots of different ways. If your experiences meet certain criteria your doctor might diagnose you with a specific anxiety disorder. Some commonly diagnosed anxiety disorders are:
• Generalised anxiety disorder (GAD) – this means having regular or uncontrollable worries about many different things in your everyday life. Because there are lots of possible symptoms of anxiety this can be quite a broad diagnosis, meaning that the problems you experience with GAD might be quite different from another person’s experiences.
• Social anxiety disorder – this diagnosis means you experience extreme fear or anxiety triggered by social situations (such as parties, workplaces, or any situation in which you have to talk to another person). It is also known as social phobia.
• Panic disorder – this means having regular or frequent panic attacks without a clear cause or trigger. Experiencing panic disorder can mean that you feel constantly afraid of having another panic attack, to the point that this fear itself can trigger your panic attacks.
• Phobias – a phobia is an extreme fear or anxiety triggered by a particular situation (such as social situations) or a particular object (such as spiders).
• Post-traumatic stress disorder (PTSD) – this is a diagnosis you may be given if you develop anxiety problems after going through something you found traumatic. PTSD can cause flashbacks or nightmares which can feel like you’re re-living all the fear and anxiety you experienced during the actual event.
• Obsessive-compulsive disorder (OCD) – you may be given this diagnosis if your anxiety problems involve having repetitive thoughts, behaviours or urges.
• Health anxiety – this means you experience obsessions and compulsions relating to illness, including researching symptoms or checking to see if you have them. It is related to OCD.
• Body dysmorphic disorder (BDD) – this means you experience obsessions and compulsions relating to your physical appearance.
• Perinatal anxiety or perinatal OCD
What’s a panic attack?
A panic attack is where you suddenly feel extremely fearful. You might have a racing heart, find it hard to breathe, or feel sweaty, dizzy, shaky or like you might vomit. Some people feel like they might collapse or die. Others feel like they’ve lost touch with reality.
The attacks come on very quickly, and can be over in just a few minutes. Sometimes they seem to happen for no reason – for example you might be just watching TV or relaxing on the couch.
Panic attacks aren’t dangerous, but they are very scary. Just because you’ve had one panic attack, it doesn’t mean you have an anxiety disorder. But it’s worth seeking help if:
• You’ve had several panic attacks, or
• You’re so worried about having another one that it affects how you live your life.
Reference
https://www.webmd.com/anxiety-panic/guide/anxiety-disorders
https://www.webmd.com/anxiety-panic/guide/generalized-anxiety-disorder
https://nexalin.com/tag/anxiety-diorder/
https://my.clevelandclinic.org/health/diseases/9536-anxiety-disorders
https://www.medicalnewstoday.com/articles/323454
https://www.helpguide.org/articles/anxiety/generalized-anxiety-disorder-gad.htm
https://adaa.org/understanding-anxiety
https://www.mayoclinic.org/diseases-conditions/generalized-anxiety-disorder/symptoms-causes/syc-20360803
https://www.verywellmind.com/anxiety-disorder-2510539