Imagine this: A woman hates to stand in line at the grocery store—not because she's impatient, but because she's afraid that everyone is watching her. As she approaches the clerk, she becomes anxious and self-conscious. Her heart begins to race, her face turns red, and she begins to sweat. She tries to say hello, but her mouth is dry and her body trembles. When she leaves the store, she can't stop thinking that she made a fool of herself. Her feelings of apprehension and embarrassment only get worse on the drive home.

If this sounds familiar, you may have social anxiety disorder, a condition that affects approximately 15 million American adults. Also known as social phobia, it often begins in childhood, typically around 13 years of age, and men and women are equally likely to develop the disorder, according to the National Institute for Mental Health (NIMH). Unlike getting the jitters before a speech or presentation, which is simply shyness, social anxiety disorder is much worse--it's the extreme, debilitating end of the shyness spectrum.

Understanding the Disorder

Social anxiety disorder is diagnosed when people become overwhelmingly anxious and excessively self-conscious in everyday social situations. People with social phobia have an intense, persistent, and chronic fear of being watched and judged by others and of doing things that will embarrass them. In fact, they can worry for days or weeks before certain situations. This fear may become so severe that it can interfere with work, school, ordinary activities, and relationships, according to the NIMH.

Social anxiety disorder affects people differently. Each person fears different situations, ranging from dealing with people in authoritative positions to using a telephone and writing in public. In these scenarios, people may experience intense anxiety that leads to nausea, trembling, muscle tension, stomach upset, diarrhea, heart palpitations, blushing, excessive sweating, dry throat or mouth, and stammering.

Assessing Your Symptoms

Still not sure if you're dealing with shyness or social anxiety disorder? Remember that dreaded speech or presentation: If you managed to deliver it despite your nerves and breathed a sigh of relief when it was over, you're probably just shy. If you called in sick to avoid it, chances are, it's social anxiety disorder. In extreme cases, sufferers can't even place a seemingly simple telephone call to order pizza, for example, because they're so worried about how the worker on the other end will react.

According to the NIMH, people experiencing these sorts of symptoms should seek medical attention as soon as possible since social anxiety disorder can become worse without treatment. And, unlike shyness, social anxiety disorder is often accompanied by depression and may even result in substance abuse if sufferers try to self-medicate. The good news is that most social anxiety disorders can be successfully treated with the right combination of medication and cognitive-behavioral therapy. So if you're experiencing any of these symptoms, be sure to consult a trained mental health professional.