Effects of stress on mind and body

Stress affects us in four ways:

• Emotional: anxiety, mood swings, depression. Examination anxiety is a common example.
• Physiological: the body releases stress hormones like adrenaline and cortisol, raising heart rate and blood pressure.
• Cognitive: poor concentration, poor memory, confused thinking.
• Behavioural: disturbed sleep, changed eating, more use of drugs, alcohol or cigarettes, absence from work.

If stress goes on too long, it causes burnout: a state of physical, emotional and psychological exhaustion. It is also linked to illness: heart disease, high blood pressure, ulcers and asthma.

Selye's General Adaptation Syndrome (GAS): how the body reacts to long-term stress, in three stages:

• Alarm reaction: the body mobilises its defences (fight or flight).
• Resistance: the body tries to cope and adapt, using up its resources.
• Exhaustion: if the stress continues, resources run out, and illness follows.

The model was criticised for giving little role to psychological appraisal: it treats all stressors as the same, while people react differently depending on how they see the situation.

Psychoneuroimmunology studies the links between the mind, the brain and the immune system. Stress weakens the immune system: it lowers the activity of natural killer cells that fight infection and tumours. (HIV is dangerous because it attacks the immune system itself.) Social support helps protect immunity.

Stress also breeds unhealthy lifestyles: poor diet, smoking, alcohol, little exercise. Healthy habits promote a longer life. Stress truly 'gets under the skin'.