A complaint of insomnia has to be analysed, and differentiated from hypochondria and, overall, from hypersomnia. Once confirmed and assessed as acute or chronic, it is often considered a disorder of hyperarousal, that is an imbalance between a central nervous system activating and a central nervous system inhibiting system with subcontinuous overflow from the former. An acute insomnia is less than one month of duration. As a disease, insomnia has to be categorized as a secondary or a primary disorder. Thereafter, it remains to assess the extent of social, psychological and economical interactions. These factors intervene as consequences or perpetuating factors. The capacity to assess the whole situation is really the great strength of the general practitioner who, more than anybody else, is on home ground. Laboratory findings and specialist examination come only as supporting evidence for causal links. A polysomnography realized in a sleep disorder center provides data reinforcing or correcting the diagnosis. From a sound assessment of the disease, the treatment has to be deduced by following a rigorous reasoning, devoid of guilty feelings as they are suggested to patients by mass-media talking, as well as freed from fashionable non medical practices. Today, we know that chronic insomnia is a disease with potential severe consequences and that it does not heal spontaneously.