They are engineers, hairdressers, communications managers, students or headmasters. Like them, hundreds of thousands of people are affected by burnout syndrome every year in France and around the world. Thousands of men and women of all ages who have suddenly collapsed, unable to move forward. In the absence of a precise diagnosis, this invisible and insidious disease slowly eats away at those who suffer from it without knowing it. So why is burn-out not recognized as an illness by the WHO? How can you spot the symptoms before it's too late? What are the warning signs? And what tools do we have to deal with it? In Europe and North America, initiatives are being put in place to prevent the onset of the disease and measure its cost to society. In France, structures are being set up to care for victims and reintegrate them into society. However, there still seems to be a long way to go before mental health in the workplace becomes a priority in today's world.