Anxiety during social interactions, particularly between strangers, is common among young people. It may persist into adulthood and become social anxiety or social phobia. "Stranger anxiety" in small children is not considered a phobia. In adults, an excessive fear of other people is not a developmentally common stage; it is called social anxiety. According to Cutting, social phobics do not fear the crowd but the fact that they may be judged negatively.
Experiencing a chronic medical condition or severe or frequent illness can also increase risk for anxiety disorders, as well as dealing with significant illness of a family member or loved one. Given that several medical conditions have been linked to significant anxiety, in some cases a physician may perform medical tests to rule out an underlying medical condition. For instance, thyroid disease is often characterized by experiencing significant symptoms of anxiety. Menopause, heart disease, and diabetes have also been linked to anxiety symptoms. Additionally, drug abuse or withdrawal for many substances is characterized by acute anxiety, and chronic substance abuse can increase risk for developing an anxiety disorder. Anxiety can also be a side effect of certain medications. Experiencing significant sleep disturbances, such as difficulty falling asleep or staying asleep, may also be a risk factor for developing an anxiety disorder.
Panic attacks may also be caused by substances. Discontinuation or marked reduction in the dose of a substance such as a drug (drug withdrawal), for example an antidepressant (antidepressant discontinuation syndrome), can cause a panic attack. According to the Harvard Mental Health Letter, "the most commonly reported side effects of smoking marijuana are anxiety and panic attacks. Studies report that about 20% to 30% of recreational users experience such problems after smoking marijuana."
Social anxiety disorder (previously called social phobia): People with social anxiety disorder have a general intense fear of, or anxiety toward, social or performance situations. They worry that actions or behaviors associated with their anxiety will be negatively evaluated by others, leading them to feel embarrassed. This worry often causes people with social anxiety to avoid social situations. Social anxiety disorder can manifest in a range of situations, such as within the workplace or the school environment.