Stress and the body: what the response does, and when to get help

A racing heart before a hard conversation, tight shoulders after a long week, a mind that will not switch off at night. These are ordinary signs of the body responding to pressure. The harder question is when that response stops being useful and starts to wear a person down. This note outlines the stress response, compares short-term and long-term stress, summarises coping ideas from the US National Institute of Mental Health (NIMH) and Mayo Clinic, and says when to seek help. It is general information, not personal advice.

What the stress response does

Mayo Clinic describes the sequence like this. When the brain senses a threat, a small area at its base called the hypothalamus sets off an alarm system. Through nerve and hormonal signals, the adrenal glands (small glands above the kidneys) release a surge of hormones, mainly adrenaline and cortisol. Adrenaline makes the heart beat faster, raises blood pressure and gives you more energy. Cortisol, the main stress hormone, raises blood sugar and helps the brain use it. It also slows body functions that are not needed in a fight-or-flight moment, such as digestion and reproductive processes.

People differ in how strongly they react. Mayo Clinic says genes, past experiences such as trauma, and the demands of daily life all play a part.

Short-term and long-term stress

NIMH defines stress as the physical or mental response to an external cause, and says a stressor may be a one-time or short-term event or something that happens repeatedly over a long time. It notes that stress can be positive or negative: it might push you to meet a deadline, or cost you sleep.

In the usual pattern, the response switches itself off once the threat has passed. Mayo Clinic says hormone levels then return to typical levels, and heart rate and blood pressure settle. The difficulty comes when stressors are always present. Then the fight-or-flight reaction stays on, and the body is exposed to cortisol and other stress hormones for too long. Mayo Clinic says this can disrupt almost all the body's processes and raise the risk of many health conditions.

Its list of possible effects is long: anxiety, depression, trouble with memory and focus; digestive upset, muscle tension and headaches; sleep difficulties; and, over time, higher risk of heart disease, high blood pressure and stroke. These are risks described by a clinical reference, not certainties for any one person.

NIMH draws a line between stress and anxiety. Stress usually has an external cause and tends to go away when the situation is resolved. Anxiety is the body's reaction to stress and can persist when there is no current threat. If that feeling does not go away and begins to interfere with life, NIMH says it can affect sleep and the immune, digestive and cardiovascular systems. NIMH's fact sheet is written for teens and young adults, though the ideas are general.

What health bodies suggest for coping

These are ideas the two sources list, not treatments. NIMH notes that finding what works can take trial and error.

• Breathing and relaxation. NIMH mentions apps with relaxation exercises such as deep breathing or visualisation, and Mayo Clinic lists yoga, deep breathing, massage and meditation.
• Activity and regular meals. Both sources mention regular exercise and healthy, regular eating. If movement helps your mood, exercise and mood looks at the evidence.
• Sleep. NIMH suggests sticking to a sleep routine; Mayo Clinic suggests turning off screens for at least an hour before bed. The NHS adds that if you often worry in bed, writing a to-do list for the next day can help clear your mind. Our note on how much sleep adults need covers the numbers.
• Talking. Mayo Clinic suggests fostering friendships and talking with people who support you. NIMH suggests reaching out to friends or family who help you cope in a positive way.
• Thinking and journaling. Both mention keeping a journal, and NIMH suggests identifying and challenging unhelpful thoughts.
• Less caffeine. NIMH suggests avoiding excess caffeine; see caffeine and sleep.

When to get help

NIMH says it may be time to talk to a professional if you are struggling to cope or if symptoms of stress or anxiety will not go away. It names psychotherapy (talk therapy) and medication as the two main treatments for anxiety, and says many people benefit from a combination. Mayo Clinic says to see a healthcare professional if symptoms continue after you have tried to manage stress, partly so other causes can be checked. For finding one, see finding a licensed therapist; related notes sit on the sleep, stress and support shelf.

Chest pain, especially with shortness of breath, sweating, dizziness, nausea or pain in the jaw, back, shoulder or arm, needs emergency help right away; Mayo Clinic says these can be warning signs of a heart attack rather than stress. Anyone in crisis or thinking about harming themselves should contact local emergency services or a crisis line. In the United States, NIMH points to calling or texting 988, or calling 911 in a life-threatening situation.

The short version

The stress response is a normal protective system, and trouble tends to start when it stays switched on. Breathing exercises, activity, regular sleep and talking to people you trust are the coping ideas most often listed by health bodies, though they work differently for different people. If stress keeps interfering with life or will not ease, talk to a clinician or counsellor, and seek emergency help for chest pain or thoughts of self-harm.