What stress is: your body and brain under pressure

Stress is not a sign that something is wrong with you. It is your body's built-in alarm system, and once you understand how it works you can use it, calm it and notice when it has been switched on for too long.

What stress actually is

• The NHS describes stress as a reaction to mental or emotional pressure, often linked to feeling that you are losing control of a situation. Sometimes there is no obvious cause at all.
• Common triggers include family difficulties, money worries, illness, injury and bereavement. For you, exams, applications, friendships and big decisions are likely triggers too.
• Good events can be stressful as well. The NHS lists positive life events such as buying a house, having a baby or planning a wedding among possible causes, which is why starting university can feel stressful even when you are excited about it.
• The NHS also points out that stress hormones can sometimes motivate you. The problem is stress that is constant and never switches off.

Fight or flight: what happens in your body

• When your brain detects a threat, the sympathetic nervous system starts the 'fight or flight' response, shifting energy towards dealing with the threat (APA).
• Your adrenal glands release adrenaline and cortisol. Cortisol raises the energy available by releasing glucose and fats into your blood.
• Your heart beats faster and harder, your blood pressure rises, your breathing speeds up and your muscles tense, ready for action.
• Once the threat passes, the parasympathetic nervous system helps your body calm down and recover. This is the 'rest' side of the system.
• That racing heart before a presentation is this same system at work. In a short burst it is your body preparing you to act.

Short-term stress versus chronic stress

• With short-term (acute) stress, your body usually returns to normal once the stressful event is over (APA).
• Chronic stress keeps the alarm system switched on for weeks or months, causing wear and tear on the body.
• The APA links long-term muscle tension from stress to tension headaches and back, neck and shoulder pain.
• Stress can also upset your digestion: the APA notes it can make stomach pain, bloating and nausea more noticeable and can increase or decrease your appetite.
• Over many years, chronic stress is linked to a higher risk of high blood pressure and heart problems, which is why learning to manage it early is worth the effort.

Positive, tolerable and toxic stress

• Researchers at Harvard's Center on the Developing Child describe three types of stress response, based on its effect on the body rather than the event itself.
• Positive stress is brief and mild, such as nerves before a test or a new class. It is a normal part of healthy development.
• Tolerable stress is more serious and longer-lasting, such as losing a loved one or a serious injury. With support from caring people, the brain and body can recover.
• Toxic stress is strong, frequent or prolonged adversity, such as abuse, neglect or exposure to violence, without supportive adults to buffer it. This is the kind that can harm health and development.
• The key difference is support. The same event can be easier to recover from when you have people around you who help.

Recognising your own stress signals

• Physical signs (NHS): headaches or dizziness, muscle tension or pain, stomach problems, chest pain or a racing heartbeat.
• Mental signs: difficulty concentrating, struggling to make decisions, feeling overwhelmed, constant worrying and forgetfulness.
• Behavioural signs: being irritable or snappy, sleeping or eating more or less than usual, and avoiding certain places or people.
• Everyone has a personal pattern. Some people get stomach aches; others cannot sleep or start snapping at siblings. Learning yours is your early warning system.
• Chest pain can have other causes. If you have chest pain or feel very unwell, get medical help and do not assume it is just stress.

Changing how you see stress

• How you interpret your stress response matters. A University of Rochester team led by psychologist Jeremy Jamieson taught community college students taking maths courses to see their stress response, such as a racing heart or sweaty palms, as something that can help performance rather than harm it.
• Compared with a control group, those students reported less maths anxiety, scored higher on an exam straight after the exercise and procrastinated less.
• You can try this yourself: instead of telling yourself 'I am so nervous, I am going to fail', try 'My body is getting ready. This energy can help me focus.'
• Reframing works best for everyday pressures like exams and performances. It is not a reason to put up with situations that are harmful or unsafe.