Anxiety is a feeling we have when we become afraid, stressed or sense that something is wrong. Feelings are normal, anxiety is normal; everyone gets anxious from time to time. Some examples, we tend to feel anxious before a test, interview, getting married and buying a house. Also, if you are in a dangerous position it is normal to feel anxious. It makes sense that a certain amount of anxiety is helpful because it helps us prepare for events and also to avoid dangerous activities.
Anxiety can be a problem if it becomes overwhelming and interferes with daily life. For example, not being able to go to work or drive because of overwhelming anxiety. If anxiety becomes overwhelming for a person and they find it difficult to cope, cognitive behaviour therapy [CBT] has been shown to help reduce anxiety. The goal is to make anxiety more manageable.
Mindfulness [MFN] activities and Progressive Muscle Relaxation [PMR] can be helpful as well. Here is a link to a site that has mindfulness downloads: