In the absence of any evidence to confirm a pathology, you will no doubt have already heard your doctor tell you that your ailments are due to... stress! To what extent is this possible? And what can we do about it?
What is stress?
Stress is an attack on the body by a physical, psychological or emotional stimulus that causes an imbalance and forces the body to adapt. In our society, stress is often seen as negative, but it was thanks to stress and the reactions it provoked that our ancestors adapted to their new environment.
There are many stressors: a verbal threat, an exam, a competition, financial or family problems, an accident, noise, etc. They always trigger an emotion (fear, anger, sadness, joy, surprise) and lead to recurrent reactions (flight, defence, shock, etc.), which are often automatic.
What are the mechanisms of stress?
The stimulus triggers reactions in the brain, reaching different parts of the body:
- The amygdala activates the reaction. It also plays an important role in recognising our emotions.
- The hippocampus is involved in environmental adaptation.
- The prefrontal cortex, the decision-making centre, is the key to our composure.
All these brain areas respond to stress at a biological level by releasing neurotransmitters and hormones.
Neurotransmitters are chemical molecules secreted by neurons in synaptic clefts and relay an excitatory or inhibitory message to receptor neurons.
At least five hormones are involved in the stress response:
- noradrenaline, a precursor of adrenaline, is released by the adrenal glands into the bloodstream. It promotes blood vessel contraction and therefore helps to increase blood pressure and heart rate.
- Cortisol, secreted by the adrenal glands, regulates blood pressure, cardiac and immune functions, and provides the brain with sufficient energy to prepare it for stress.
- Adrenocorticotropin (ACTH) is secreted by the pituitary gland, which is itself activated by a hormone released by the hypothalamus. ACTH then circulates in the bloodstream and triggers the release of cortisol from the adrenal glands.
- oxytocin, a social bonding and attachment hormone that regulates anxiety, is produced mainly by the hypothalamus (where it also plays a role as a neurotransmitter) and circulates in the blood to be distributed to the organs.
- vasopressin antidiuretic hormone, increases water permeability and therefore reduces urine volume, regulates blood pressure as a vasoconstrictor, plays a role in anxiety.
What happens if exposure to stress persists over time?
In the face of short-term stress, the senses are alert, enabling a rapid adaptation response.
On the other hand, if exposure to stress is prolonged, hormones are secreted without interruption, leading to exhaustion of the body. Circulating sugar levels (blood sugar) fall, cells are no longer nourished, cholesterol is no longer regulated and the hormonal system is deregulated. The body is no longer able to defend itself effectively and becomes a breeding ground for disease.
Chronic stress also has repercussions on the emotional and behavioural state and on cognition: depression, constant aggression, emotional fatigue, irritability, difficulty concentrating (thoughts focused on the stressor), memory problems, heightened anxiety, emotionality, agitation and disturbed sleep.
As you can see, over a long period of time, even when subjected to "minimal" stress, your body will change, particularly its pH level, making it more acidic, which is conducive to inflammation and the onset of disease.
How can you combat stress?
It's important to know how to listen to your body, so that you can detect the signs and symptoms of the effects of stress. Then we need to be able to identify the stressors around us (which is a very individual perception, since one person's stress is not necessarily another person's stress...). Understand our own (often automatic) reactions to stressful situations, so that we can thwart our own unconscious mechanisms.
In this way, it becomes possible to consciously counter-balance the 'negative' effects of stress, which lies in hormonal balance.
The antidote to cortisol is endorphin!
Endorphin is the pleasure hormone, and is secreted when you engage in physical activity (walking, running, cycling, etc.), meditate, listen to music, etc. Activities such as painting, writing or chatting with friends are also sources of relaxation and can help you to manage stress better.
So don't deprive yourself of getting moving and keeping your mind occupied with all kinds of artistic or creative activities... the new school year is here and it's a good time to make new resolutions: in particular, to stop letting stress ruin our lives and our health!
