Anxiety can be an appropriate or inappropriate response to threats of many types. An appropriate response would be to become anxious regarding threatening circumstances (physical, emotional, financial threats). In this case, taking immediate action to reduce the threat would be appropriate. If the threat is going to be prolonged and can not be changed, then how the threat is viewed must be changed to reduce the likely mental and health consequences. Simple anxiety commonly results from chronic stress. Mental health professionals speak of "anxiety disorders", of which there are multiple types - Generalized Anxiety Disorder, Panic Disorder, Obsessive-compulsive Disorder, Post-traumatic Stress Disorder, Agoraphobia, Social Anxiety - to mention a few. In addition to anxiety, other psychological or physical symptoms can be experienced.

People with social anxiety disorder do not believe that their anxiety is related to a medical or physical illness or disease. This type of anxiety occurs in most social situations, especially when the person feels on display or is the center of attention.

People with panic believe very strongly that the "panic attack" they experienced means that something is physically wrong with them. People with panic disorder can be checked, rechecked, and repeatedly use the hospital emergency rooms before it ever becomes clear to them that they are legitimately suffering from anxiety, and not a physical, medical condition.
The central point is that people who experience panic attacks fear that they have a physical, medical disease.

Psychological symptoms associated with anxiety may include overwhelming worry, apprehension, nervousness and a nagging uneasiness about the future. Physical symptoms can include rapid heartbeat and palpitations, sweating, dizziness, headaches, insomnia and relentless fatigue. The set of symptoms that an individual experiences helps physicians diagnose their specific disorder. Anxiety disorders, like depression, may run in families and be linked to an imbalance in neurotransmitters. Anxiety symptoms are often relieved when the depression is successfully treated.

If anxiety is disproportional to life's circumstances and there are no obvious underlying reasons for the it, psychological and biochemical disturbances should be investigated. Alternative medicine has a lot to offer in this respect, common recommendations including avoiding caffeine, sugar and alcohol. Hidden food allergies may be a contributing factor or cause.

Nutrients such as calcium and magnesium, B vitamins, niacinamide, B12 injections (especially if stomach acid production is insufficient), tryptophan with inositol and chromium, valerian root, and GABA can have a calming effect.

In people with chronic anxiety unrelated to life events, an injection of sodium lactate will trigger a panic attack. Eating a lot of foods high in refined sugar increases blood lactate levels and can induce panic in susceptible persons. Eliminating caffeine and alcohol and refined sugars from the diet is essential for anyone suffering from anxiety.