DISCLAIMER: Because each body is somewhat chemically unique, and because each person will have a unique mix of symptoms and underlying factors, recovery results may vary. Variances can occur for many reasons, including due to the severity of the condition, the ability of the person to apply the recovery concepts, and the commitment to making behavioral change.
Selective mutism: A somewhat rare disorder associated with anxiety is selective mutism. Selective mutism occurs when people fail to speak in specific social situations despite having normal language skills. Selective mutism usually occurs before the age of 5 and is often associated with extreme shyness, fear of social embarrassment, compulsive traits, withdrawal, clinging behavior, and temper tantrums. People diagnosed with selective mutism are often also diagnosed with other anxiety disorders.
Social Anxiety Disorder;Fear of social situations in which the person is exposed to unfamiliar people or to possible scrutiny by others. The individual fears that he or she will act in a way (or show anxiety symptoms) that will be embarrassing and humiliating, often times leading to avoidance of social situations and severe distress when participation in social situations can't be avoided. 
There are two very important guidelines to think about, aside from symptoms. These are duration of symptoms and level of impairment. Anxiety is a normal reaction to stressful situations, and even high levels of anxiety can be healthy and beneficial at times. Disorders are only present when anxiety symptoms last for several weeks to months and significantly interfere with every day function or cause long-lasting distress.
Fear and anxiety are part of life. You may feel anxious before you take a test or walk down a dark street. This kind of anxiety is useful - it can make you more alert or careful. It usually ends soon after you are out of the situation that caused it. But for millions of people in the United States, the anxiety does not go away, and gets worse over time. They may have chest pains or nightmares. They may even be afraid to leave home. These people have anxiety disorders. Types include
Test anxiety is the uneasiness, apprehension, or nervousness felt by students who have a fear of failing an exam. Students who have test anxiety may experience any of the following: the association of grades with personal worth; fear of embarrassment by a teacher; fear of alienation from parents or friends; time pressures; or feeling a loss of control. Sweating, dizziness, headaches, racing heartbeats, nausea, fidgeting, uncontrollable crying or laughing and drumming on a desk are all common. Because test anxiety hinges on fear of negative evaluation, debate exists as to whether test anxiety is itself a unique anxiety disorder or whether it is a specific type of social phobia. The DSM-IV classifies test anxiety as a type of social phobia.
"This tends to make the individual vulnerable to developing an anxiety disorder, rather than cause them to directly inherit one," she says. Environmental factors, she adds, interact with genetic predispositions to trigger the onset of anxiety disorders. A study published in August 2017 in the journal Emotion may offer clues as to how both genes and environment combine to make anxiety take root. (4)
Because involuntary panic attacks can be caused by other medical conditions, such as mitral valve prolapse, thyroid problems, hyperglycemia, side effects from certain types of medications, recreational drug use (such as marijuana), stimulants, etc., it’s best to discuss your panic attacks and symptoms with your doctor to rule out any medical cause.
Panic attacks (or anxiety attacks - the terms are interchangeable) are intense episodes of fear which are so powerful that they trick you into fearing that you are dying, going crazy, about to faint, or losing control of yourself in some vital way. The symptoms of a panic attack feel so powerful and threatening that they convince you that you're in terrible danger.
As is true for other mood and anxiety disorders, the use of Selective Serotonin Reuptake Inhibitors (SSRI's; e.g.., Paxil, Prozac, Zoloft), Benzodiazepines (e.g., Xanax, Lorazepam), and Selective Norepinephrine Reuptake Inhibitors (SNRI's; e.g., Cymbalta, Effexor, Pristiq) are common medical treatments for panic disorder. Additionally, D-cycloserine is a medication that is now being explored as a way to enhance effects of CBT (e.g., Hofmann et al., 2013). These medications may have side effects and taking them can lead to tolerance, withdrawal symptoms, and dependence, so it is important that you consult with a physician before starting or stopping these medications. There is evidence that taking one of these medications in addition to receiving behavioral therapy (e.g., CBT) can significantly benefit patients with panic disorder, although seeking psychotherapy in itself is largely effective (Arch et al., 2017).
We all experience anxiety. For example, speaking in front of a group can make us anxious, but that anxiety also motivates us to prepare and practice. Driving in heavy traffic is another common source of anxiety, but it helps keep us alert and cautious to avoid accidents. However, when feelings of intense fear and distress become overwhelming and prevent us from doing everyday activities, an anxiety disorder may be the cause.
Expected panic attacks are those which occur when you are exposed to one of your triggers. For example, if you have a fear of flying you may have a panic attack when you board a plane. Expected panic attacks are again broken down into two categories: situationally bound (cued) in which a person is anticipating exposure to a particular trigger (as with our flying example), or situationally predisposed, in which a panic attack does not always occur when exposed to the feared situation.
Panic attacks are generally brief, lasting less than 10 minutes, although some of the symptoms may persist for a longer time. People who have had one panic attack are at greater risk for having subsequent panic attacks than those who have never experienced a panic attack. When the attacks occur repeatedly, and there is worry about having more episodes, a person is considered to have a condition known as panic disorder.
Antidepressants called selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) are commonly used as first-line treatments for anxiety. Less-commonly used — but effective — treatments for anxiety disorders are older classes of antidepressants, such as tricyclic antidepressants and monoamine oxidase inhibitors (MAOIs).