What causes anxiety disorders and what are their symptoms?

There are several possible reasons for anxiety disorders, including biological and environmental factors such as genetics, biochemical changes in the brain and traumatic life events.

Symptoms may include:

• Panic, fear, apprehension
• Uncontrollable obsessive thoughts
• Repeated flashbacks of traumatic experiences
• Nightmares
• Ritualised behaviour such as repeated hand-washing
• Problems sleeping
• Cold or sweaty hands
• Palpitations
• Shortness of breath
• Inability to be still and calm
• A dry mouth
• Numbness or tingling in the hands or feet
• Upset stomach
• Tense muscles

Often there appears to be no particular reason why symptoms occur since the feelings of panic are dissociated from events which are happening or about to occur.

But they can be extremely disabling and have a great effect on the person's friends and family and their ability to work.

People who suffer from anxiety disorders may also have other mental illnesses, such as depression.

Anxiety disorders often respond well to treatment.

This can include behavioural therapy, counselling to find out the cause of the anxiety, relaxation techniques and drugs which control the symptoms or correct chemical imbalances.

Panic disorders

People who suffer from these disorders have repeated panic attacks which are often difficult to predict.

Symptoms include sweating, shaking, shortness of breath, nausea, dizziness, fear of dying or losing control and hot flushes.

Some symptoms, such as chest pain, can mimic those of a heart attack, increasing the sense of anxiety.

Panic disorders usually first occur in late adolescence or early adulthood.

Women are thought to be twice as likely to suffer from them as men.

Research suggests the condition is sometimes genetically inherited.

Phobias

Phobias are irrational, persistent and uncontrollable fear of something.

Common phobias include agoraphobia - fear of open spaces, claustrophobia - fear of closed spaces, social phobia and fears of specific objects, such as spiders or snakes.

The fear can be so overwhelming that people go to great lengths to avoid the situation or thing they are afraid of.

People with severe agoraphobia, for example, may find it difficult to venture out of their homes.

Obsessive compulsive disorder

People who have obsessive compulsive disorders resort to ritualised behaviour as a means of overcoming irrational fears.

Common obsessions include fear of dirt or germs, a need for absolute tidiness or order and repeated doubts, for example, about turning off electrical or gas appliances.

The person often realises their behaviour is irrational, but this alone does not help to dispel their fears.

Compulsive behaviour includes repeated hand washing, following rigid patterns of behaviour, such as putting on clothes in the same order every day or avoiding cracks in the pavement.

Many people have compulsive behaviour, but it is only when it begins to interfere with daily activities and relationships that it becomes a serious disorder.

Obsessive compulsive disorders often start in adolescene or early adulthood and may be linked to other mental health problems, such as depression.

Post-traumatic stress disorder

Post-Traumatic Stress Disorder (PTSD) follows a severe of terrifying emotional experience.

Events which may trigger PTSD include serious accidents, violent attacks, abuse and war.

Often emergency staff suffer from PTSD as a result of dealing with trauma.

They may experience extreme distress, including unexpected flashbacks to the event, nightmares, depression, detached feelings, trouble being close to members of their families, irritability and mood swings and even feelings of violence.

Symptoms usually begin within three months of the trauma, but sometimes they start many years later.

Sometimes they only last for a short period, but they may be long-lasting if no help is received.

Medication such as antidepressants or anxiety-reducing drugs can treat symptoms like depression and insomnia and therapy can help with coming to terms with the trauma.