01
What it is
Stress is your body's response to a demand: a deadline, an argument, a sick parent, a long commute. The World Health Organization describes it as a state of worry or mental tension caused by a difficult situation, and a natural human response that prompts us to deal with challenges.
In short bursts, stress is useful. It sharpens your attention, speeds your reactions and gives you energy to act. The trouble starts when the alarm never switches off.
02
What happens in your body
Within seconds of a threat, your brain's alarm centre, the amygdala, signals the hypothalamus. Two systems then start at once.
- The fast route: nerves tell the adrenal glands to release adrenaline. Your heart beats faster, you breathe more quickly and sugar floods into your blood.
- The slower route, called the HPA axis (the brain-to-gland chain that controls stress hormones): the hypothalamus signals the pituitary gland, which signals the adrenal glands to release cortisol, the main stress hormone.
The stress-hormone chain
- 1BrainThe hypothalamus senses a threat
- 2PituitarySends a signal hormone (ACTH)
- 3AdrenalsGlands above the kidneys respond
- 4CortisolRaises blood sugar and alertness
Off switch: cortisol tells the brain to stop the alarm. In long-term stress, this signal weakens.
Source: Chrousos, Nat Rev Endocrinol 2009
Text version
The stress-hormone chain (HPA axis). 1. Brain: the hypothalamus senses a threat. 2. Pituitary: sends a signal hormone called ACTH. 3. Adrenals: the glands above the kidneys respond. 4. Cortisol: raises blood sugar and alertness. Off switch: cortisol tells the brain to stop the alarm; in long-term stress this signal weakens.
Cortisol keeps you fuelled and alert for the next few hours. Normally, rising cortisol is also the off switch: it tells the brain to stop sending the alarm. In long-term stress, that feedback weakens, and the system stays partly switched on.
03
Why it happens
Your stress system cannot tell the difference between a tiger and an inbox. Anything you read as a threat (to your safety, your money, your relationships or your sense of control) starts the same chain.
- Pressures that never end, such as caring for someone, money worries or an insecure job
- Too little recovery: short sleep, no breaks, no time outdoors
- Repeated small alarms, such as constant notifications and news
- Caffeine and alcohol, which both disturb sleep and so weaken recovery
Researchers call the wear and tear from a system that keeps firing “allostatic load”. It builds up quietly and shows up in many parts of the body at once.
04
How it affects you
Where stress shows up
Long-term stress
- 1MindRacing thoughts, irritability
- 2SleepTrouble falling or staying asleep
- 3HeartFaster pulse, higher blood pressure
- 4GutAcidity, bloating, changed bowels
- 5SkinAcne and eczema flare-ups
- 6MusclesTight neck, jaw and shoulders
Sources: WHO 2023; McEwen, NEJM 1998
Text version
Long-term stress shows up across the body. Mind: racing thoughts and irritability. Sleep: trouble falling or staying asleep. Heart: faster pulse and higher blood pressure. Gut: acidity, bloating and changed bowels. Skin: acne and eczema flare-ups. Muscles: tight neck, jaw and shoulders.
- Mind: racing thoughts, irritability, trouble concentrating
- Sleep: difficulty falling asleep, waking at 3 or 4 a.m.
- Gut: acidity, bloating, loose stools or constipation
- Heart: higher blood pressure and heart rate over time
- Skin: flare-ups of acne, eczema and psoriasis
- Muscles: tight neck, shoulders and jaw; tension headaches
These effects feed each other. Poor sleep makes the next day's stress feel bigger, and worry makes sleep worse.
The stress, anxiety and sleep loop
- StressCortisol stays high at night
- Poor sleepThe brain's alarm becomes more reactive
- AnxietySmall worries feel bigger
Sources: Chrousos 2009; AASM/SRS 2015
Text version
Stress keeps cortisol high at night, which leads to poor sleep. Poor sleep makes the brain's alarm more reactive, which feeds anxiety. Anxiety makes small worries feel bigger, which adds to stress. Breaking any one link helps the others.
05
What you can change
You cannot remove every pressure, but you can give your body clear signals that the danger has passed. The best evidence supports simple, regular habits.
- Breathe slowly: five minutes of breathing out for longer than you breathe in (for example in for 4, out for 6) helps calm the heart rate.
- Move every day: a 30-minute brisk walk lowers stress hormones and improves sleep.
- Protect your sleep window: the same bedtime and wake time every day, including weekends.
- Get morning daylight: 10 to 20 minutes outside soon after waking helps set your body clock.
- Cut caffeine after 2 p.m. and keep alcohol low.
- Talk to someone: a friend, family member or counsellor. Connection is one of the strongest buffers against stress.
06
When to see a doctor
See a doctor if stress has lasted more than a few weeks and is getting in the way of work, study or relationships; if you are sleeping badly most nights; if you have chest pain, palpitations or frequent headaches; or if you are using alcohol or other substances to cope.
If you feel overwhelmed or have thoughts of harming yourself, call Tele-MANAS on 14416 (free, 24 hours, many Indian languages), or 112 in an emergency.
07
The Ayurvedic view
Ayurveda describes long-term stress mainly as a disturbance of Vata, the dosha (functional pattern) of movement, together with excess Rajas, the quality of agitation in the mind. The picture it paints (a restless mind, broken sleep, a nervous stomach, dry skin) matches the modern description surprisingly well.
The classical approach is to steady the routine before reaching for herbs. It recommends regular meal and sleep times (Dinacharya, the daily routine), warm and simple food, self-massage with warm oil (Abhyanga) and calm evenings, all aimed at rebuilding Ojas, the reserve of resilience.
Among herbs, Ashwagandha is the best studied. Small randomised trials found lower stress scores and morning cortisol after six to eight weeks of root extract, but the studies were short and small, and rare liver injury has been reported. It is not right for everyone: see the herb page for who should avoid it, and talk to your doctor first.