While panic disorder in adolescents tends to have similar symptoms as in adults, symptoms of this condition in younger children are less likely to include the thought-based or so-called cognitive aspects. Specifically, teenagers are more likely to feel unreal or as if they are functioning in a dream-like state (derealization) or be frightened of going crazy or of dying.
If you have a debilitating fear of being seen negatively by others and humiliated in public, you may have social anxiety disorder, also known as social phobia. Social anxiety disorder can be thought of as extreme shyness. In severe cases, social situations are avoided altogether. Performance anxiety (better known as stage fright) is the most common type of social phobia.
The emotional effects of anxiety may include "feelings of apprehension or dread, trouble concentrating, feeling tense or jumpy, anticipating the worst, irritability, restlessness, watching (and waiting) for signs (and occurrences) of danger, and, feeling like your mind's gone blank" as well as "nightmares/bad dreams, obsessions about sensations, déjà vu, a trapped-in-your-mind feeling, and feeling like everything is scary."
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. 
While the term "test anxiety" refers specifically to students, many workers share the same experience with regard to their career or profession. The fear of failing at a task and being negatively evaluated for failure can have a similarly negative effect on the adult. Management of test anxiety focuses on achieving relaxation and developing mechanisms to manage anxiety.
Please note that it is not a good idea to attempt to diagnose or label a friend or family member. Only a mental health professional can diagnose an anxiety disorder, as many disorders have overlapping features, and can go together with other types of mental health difficulties. However, if you notice signs of anxiety, or just feel that something is not quite right with someone that you care about, it's a good idea to reach out to ask the person how they are feeling. You could start with something neutral and supportive like, "It seems like you haven't been quite yourself lately. Is there something going on that you want to talk about?"
Characterized by the development of certain trauma-related symptoms following exposure to a traumatic event (see "Diagnostic criteria" below). While most people experience negative, upsetting, and/or anxious reactions following a traumatic event, a diagnosis of PTSD is made when symptoms and negative reactions persist for more than a month and disrupt daily life and functioning. Symptoms are separated into four main groups: re-experiencing, avoidance, negative cognitions and mood, and hyperarousal. The specific symptoms experienced can vary substantially by individuals; for instance, some individuals with PTSD are irritable and have angry outbursts, while others are not. In addition to the symptoms listed below, some individuals with PTSD feel detached from their own mind and body, or from their surroundings (i.e., PTSD dissociative subtype).
Seeing a friend or loved one suffering a panic attack can be frightening. Their breathing may become abnormally fast and shallow, they could become dizzy or light-headed, tremble, sweat, feel nauseous, or think they’re having a heart attack. No matter how irrational you think their panicked response to a situation is, it’s important to remember that the danger seems very real to your loved one. Simply telling them to calm down or minimizing their fear won’t help. But by helping your loved one ride out a panic attack, you can help them feel less fearful of any future attacks.
Panic attacks involve sudden feelings of terror that strike without warning. These episodes can occur at any time, even during sleep. People experiencing a panic attack may believe they are having a heart attack or they are dying or going crazy. The fear and terror that a person experiences during a panic attack are not in proportion to the true situation and may be unrelated to what is happening around them. Most people with panic attacks experience several of the following symptoms:
Most of the symptoms of a panic attack are physical, and many times these symptoms are so severe that you may think you’re having a heart attack. In fact, many people suffering from panic attacks make repeated trips to the doctor or the emergency room in an attempt to get treatment for what they believe is a life-threatening medical problem. While it’s important to rule out possible medical causes of symptoms such as chest pain, elevated heart rate, or difficulty breathing, it’s often panic that is overlooked as a potential cause—not the other way around.
So, if anxiety has so many negative effects, why is it relatively common? Many scientists who study anxiety disorders believe that many of the symptoms of anxiety (e.g., being easily startled, worrying about having enough resources) helped humans survive under harsh and dangerous conditions. For instance, being afraid of a snake and having a "fight or flight" response is most likely a good idea! It can keep you from being injured or even killed. When humans lived in hunter-gatherer societies and couldn't pick up their next meal at a grocery store or drive-through, it was useful to worry about where the next meal, or food for the winter, would come from. Similarly avoiding an area because you know there might be a bear would keep you alive —worry can serve to motivate behaviors that help you survive. But in modern society, these anxiety-related responses often occur in response to events or concerns that are not linked to survival. For example, seeing a bear in the zoo does not put you at any physical risk, and how well-liked you are at work does not impact your health or safety. In short, most experts believe that anxiety works by taking responses that are appropriate when there are real risks to your physical wellbeing (e.g., a predator or a gun), and then activating those responses when there is no imminent physical risk (e.g., when you are safe at home or work).
Panic Disorder: People with panic disorder have panic attacks with feelings of terror that strike suddenly and repeatedly with no warning. During the attacks, individuals may feel like they can't breathe, have lost control, are having a heart attack or even that they are dying. Physical symptoms may include chest pain, dizziness, nausea, sweating, tingling or numbness, and a racing heartbeat. Some people will have one isolated attack, while others will develop a long term panic disorder; either way, there is often high anxiety between attacks because there is no way of knowing when the next one will occur. Panic disorders often begin early in adulthood. Many people with panic disorder also suffer from agoraphobia (abnormal fear of open or public places.). See more on Panic Attacks.
Antidepressants can take time to work, so it’s important to give the medication a chance before reaching a conclusion about its effectiveness. If you begin taking antidepressants, do not stop taking them without the help of a doctor. When you and your doctor have decided it is time to stop the medication, the doctor will help you slowly and safely decrease your dose. Stopping them abruptly can cause withdrawal symptoms.