You feel pumped
Stress triggers the brain’s amygdala to send messages to the hypothalamus gland, which in turn releases hormones into the central nervous system, which controls such things as breathing, heartbeat and digestion. For immediate threats, it releases adrenaline. This can trigger the heart to beat faster, your muscles to tense and your breathing to quicken.
You have butterflies in your stomach
The adrenal glands release cortisol, known as the stress hormone. It can regulate the body’s workings to make you more responsive to the stressful threat. For example, your digestive system needs less blood than the limbs you need to run, so it is diverted, causing an empty, fluttery feeling known as butterflies.
You feel sick (again)
Repeated release of cortisol, such as when you are chronically stressed, can depress your immune system, leaving you prone to colds and infections.
With repeated or chronic stress, your brain shrinks in areas that are linked to emotion and physiological functions, such as blood pressure and glucose levels, according to scientists at Yale. Even people who had only recently experienced a stressful event “showed markedly lower grey matter in portions of the medial prefrontal cortex”. Luckily, the brain is resilient and can recover if the stress is dealt with.
You feel older than you are
Researchers at Duke University tested the DNA of children exposed to chronic stress, such as bullying or violence at home. It showed that stress had caused damage to cells that was equivalent to several years of ageing.