Anxiety is a feeling of uneasiness, worry, or fear. It can be mild or severe, and it can last for a short time or a long time. People with anxiety may have physical symptoms such as a fast heart rate, sweating, and shaking. They may also have mental symptoms such as feeling restless, tense, or easily annoyed. Anxiety is different from fear, which is a response to a specific threat. Anxiety is a general feeling of worry or unease.