Obsessive-compulsive disorder / O.C.D - When a person has repeating, distressing and intrusive thoughts of images and urges to perform certain actions or rituals over and over, this person may have OCD. In general, such a person knows that these actions are not rational but still has trouble stopping the behavior. Their excessive fears of things that are otherwise minor cause them to repeatedly take precautionary or salutatory measures to that end. Washing hands repeatedly for fear of infections, and constantly checking that the door is locked when going out for fear of burglary are some examples of OCD behavior.

Panic Disorder/Anxiety attacks/panic attacks
This type of anxiety disorder is used to describe a person who experiences random panic attacks in day-to-day life without any apparent cause or triggers. A panic attack can consist of sweatiness, chest pains, severely elevated heartbeat, choking or symptoms that feel like a heart attack, difficulty breathing, wet palms, and trembling of the body.

Specific phobias
When a person experiences extreme fear of a particular stimulus or situation, we call this a phobia. Flying, blood, spiders, germs and snakes are examples of phobias that are commonly experienced. When facing their phobias, people will tend to freeze up; experience severe tremors; have a racing and pounding heart; and have rapid, shallow breathing.

PTSD or Post-traumatic stress disorder
Victims of an extreme situation – death of a loved one, diagnosed with cancer, domestic violent, combat, child abuse, rape or natural disasters – may develop PTSD. People with this type of anxiety disorder tend to be excessively vigilant, experience flashbacks of the extreme events, see everything as threats, experience excessive anger, and may have sleep problems.

Social anxiety - fear of public speaking, Inability to express ideas to a group.
Social anxiety disorder is also known as social phobia. People with this disorder are fearful of social situations in which they might feel embarrassed or judged. They typically feel nervous spending time in social settings, feel self-conscious in front of others, and worry about being rejected by or offending others. Other common symptoms include having a hard time making friends, avoiding social situations, worrying for days before a social event, and feeling shaky, sweaty, or nauseous when spending time in a social setting.

Separation anxiety disorder - Fear of losing someone or being alone. 

Generalized Anxiety Disorder (GAD)
A person with this type of anxiety disorder has excessive worries about everyday matters for a long period of time (typically 6 months or more). Some other symptoms of GAD include restlessness, fatigue, trouble concentrating, irritability, muscle tension and sleep disturbances. Such a person may also have trouble making commitments, and find it tough to decide on day-to-day matters.