What causes anxiety disorders?

We do not fully understand what causes anxiety disorders. But it is thought that the following factors can cause anxiety: 

• Genetics.  Some people seem to be more anxious than others at birth. You may be having anxiety through your genes. 
• Life experience . This can be bad experiences, such as being bullied or losing a loved one. It can also include major life changes, such as moving home, losing a job or getting pregnant.
• Drugs. Caffeine in coffee and alcohol can make you feel anxious. Illegal drugs, also known as street drugs, can also affect you. 
• Circumstances. Sometimes you know what is causing your anxiety. When the problem goes, your anxiety goes away as well.