Whereas in the case of anxiety the specific cause may not always be so obvious which in itself then tends to exacerbate the anxious state because the person suffering from the anxiety doesn't know what is causing it. In general terms we can look at stress as being a more generic type of mental and emotional state of lesser intensity where the person experiencing the stress often has a reasonably good idea of the cause. In the case of anxiety there is a build up of mental and emotional stress usually in relation to a specific, though often unknown, cause.
Excessive emotional disturbances such as grief generalized worry and fear as well as physical conditions such as hypoglycemia, hypoadrenia and an overactive thyroid are just some physical conditions that can lead to increased levels of stress.
Irrespective of what the specific causes are in effectively treating stress and anxiety the cause does need to be found. This is not always easy but a good place to start is mapping out your symptoms and making note of the situations and circumstances that are associated with high levels of stress and the occurrence of your anxiety attacks.
Once the cause of the stress and anxiety has been uncovered finding someone who you can talk to openly about your specific issue is often advised. Whether that person be a professional therapist, a support group or simply someone who you can talk things out with, finding someone to talk with and work out some solutions that are appropriate, and most importantly that you will follow through with, is often the best form of self help in these situations.
Whatever treatment you choose for your anxiety you must also make sure that how you live day to day supports that treatment. Proper sleep and rest, adequate nutrition and regular exercise will support whatever therapeutic approach you are taking.
Sometimes the levels of stress and anxiety bring the sufferer to breaking point in which case self help techniques are often not enough. If you or someone you know begins to experience severe physical symptoms or suicidal self destructive thoughts you must seek urgent medical attention. Self help techniques may still be able to help you but in a more supportive rather than a primary role.