There is a difference between anxiety and panic attacks:The differences between panic and anxiety are best described in terms of the intensity of the symptoms and length of time the predominant symptoms occur.
Panic Attacks
During a panic attack, the symptoms are sudden and extremely intense. These symptoms usually occur “out of the blue,” peak within 10 minutes and then subside. However, some attacks may last longer or may occur in succession, making it difficult to determine when one attack ends and another begins.
Anxiety
Anxiety, on the other hand, generally intensifies over a period of time and is highly correlated to excessive worry. The symptoms of anxiety are very similar to the symptoms of panic attacks.
While Anxiety and Panic share similar symptoms, anxiety is generally less intense. Another important distinction is that, unlike a panic attack, the symptoms of anxiety may be persistent and very long lasting -- days, weeks or even months. References: Diagnostic and Statistical Manual of Mental Disorders, 4th ed.