Loneliness is not dangerous in principle, but problematic issues that are incompatible with life can arise as a result of the discrepancy between the desire (habit) and the possibilities of socialization of a specific individual and in specific life conditions.
That is, it is not the problem that is important, but the attitude towards it and the skills of adaptation (adaptability).
Psychologist Andrey Kashkarov says that each person has characteristic features, and in principle people are divided into several general psychotypes; their preferences (and habits) change depending on the age, circumstances, living conditions and even the medical health of the individual.
Individuality "hides" the peculiarities of not only today, but also tomorrow's prospects. There is a saying about when a person is most lonely, and its answer is "only in the circle of friends."
So, the first formative factor is character traits, the other is a conditional habit, "second nature". The problem is only in the discrepancy, in the contrast. And the more sudden, the brighter the contrast between habit and reality, the higher the risk of death or degradation.
If you are not used to active communication and are not yet a sociopath (very specific signs and definitions apply to the latter), if you prefer to “read” than to go to a company in the open air, to the theater or to the cinema, and at the same time you are dragged there by force, it may very well be that you will feel loneliness and discomfort, even if you put on a sweet smile “for society.”
And vice versa, if a person is socially active, accustomed to compliments, smiles, communication, and he is forcibly isolated in the manner of Robinson Crusoe or even worse in the conditions of the penitentiary system in the manner of the experience of Edmond Dantes, this form of loneliness is also unbearable, although a person is a creature with a huge reserve of adaptability and habits can inertly change under the influence of circumstances.
The third variant of conditional loneliness is when an elderly person, who has seen a lot (and is experienced in communicating with people), moves from vigorous activity at work or in the family (raising children) to inactivity (living on vacation) or in the absence of grown-up children who have left the parental nest.
Such a contrast is also dangerous and requires adaptation skills. Of course, to maintain mental health, any transition from one to another must be done as smoothly as possible, in "steps", with preparation.
But here we come to the most interesting thing - does he have the strength and skills to adapt to the new and unusual circumstances of loneliness, which he subconsciously always fears. Here the maxim "what does not kill us makes us stronger" is truer than ever. Hence, in deciding the question of life and death, it is important how exactly you will react to the new challenges of the time, associated with loneliness in one form or another.
Loneliness is not always physical or intellectual isolation. You can live in a large family and feel lonely. You can live with your husband for 30 years and realize that you don’t know him at all, essentially, you are alone.
You are lonely if you cannot confide in each other your innermost thoughts, if you worry about the other person’s reaction, if you do not find support, if you do not enjoy communication when you “don’t pretend to impress” and act on the call of your heart, remaining yourself, that is, you do not think at all about how to choose your words, sit with your legs crossed, or even hiccup.
It is impossible to play a role all the time, so a person is, of course, oppressed by the cumulative effect of the need to correspond to something or someone's idea of themselves. This uncomfortable state, based on the fact that you are not accepted as you are, also gives rise to loneliness, longing for another, better communication, melancholy.
By the same logic, the uncomfortable state of "loneliness" is based on a crisis of personal non-realization. Often, the problem is influenced by the type of occupation or profession. A writer rarely dies of loneliness, while his creative brother - a theater actor - needs communication, because "an artist needs an audience"; the latter type can wither away without theater rehearsals. But here too, it is necessary to make an allowance for character, its elements differ in everyone.
A writer, as a person (by definition) inclined to fiction, rarely experiences loneliness, rather, on the contrary, he bathes in it. This type extremely needs solitude, at least occasionally, in order to concentrate.
After all, creative people live mostly in a world they have invented, they are not bored with themselves, and it is extremely stupid to measure them with a common yardstick. They simply will not understand you; despite the fact that neither you nor they are good and worthy people. After all, in order to understand, you need to live for some time in the same conditions, with the same thoughts... Try to "immerse" such a type in a "motley" society and lock him there, he may die of loneliness, even when there are hundreds of smiling faces around.
Therefore, the conditional recipe is simple. In order not to perish, smooth transitions from one habit to another are needed, preferably with compensation of feelings, motives and relationships. Then both the brain (development of the intellectual component) and physiological habits (activity) do not lose their meaning, the motivation for life changes, but remains influential, and life goes on, and a person adapts to new circumstances.
The most critical thing, again, occurs when this compensation does not occur. You can be a person who is not boring for yourself, like E. Hemingway, or gush with poetic forms, like V. Mayakovsky (in both examples there was not even a hint of a material crisis), and come to one final conclusion - in the absence at the right moment of a friend or sympathizer nearby with the condition of not having lost trust in him.
Or you can be a sociable mechanic in a company at a wagon-building plant, not worry about anything in particular, and wither away in six months from lack of demand at work, having retired and regularly visiting a “bar” out of boredom.