Why do we miss?
The continuous verb tense of the word missing already shows its progressive aspect. I am more than sure that; the pressure felt in the middle of the chest when someone you were used to be with is not there anymore; could never be more alive overtime. Missing is more than remembering, but why do we miss?
Missing is more than just remembering those good moments lived with that person who is not there anymore. The real problem of missing someone resides in the emptiness that is created when someone is left behind. That empty space must be filled in. However, sometimes; the solution is not always to let someone else in.
Is the pressure in the middle of my chest normal when I breath?
Indeed, yes. Luckily or unluckily you might have experienced this characteristic feeling when losing someone. People might have laugh at you when sharing this feeling, but it is actually biologically normal. This pressure is triggered by a certain state of mind termed as loneliness .
Being alone does not necessarily make a person lonely.
It is the perception of being alone which makes the person lonely . And how this perception is triggered and how is it felt; might differ from person to person. It might not be strange now to know that; current research has reported that loneliness might have a genetic basis. This evidence relies mostly to dopamine-related and serotonin-related genes . Previous research has shown that variations of the oxytocin receptor gene (OXTR) can influence social behaviors and modulate the generation of affectivity and emotional loneliness , .
Do we want to miss?
We don’t want to miss; however it is something that we can’t control and that hurts. Beyond the need of having that person or situation which is absent, what really makes us feel lonely is the oppression in the chest, the higher cardiac rhythm, and the tears from our eyes. It is the hole that has been emptied and that we can not fill what makes us feel lonely.
Loneliness has been associated with higher blood pressure , and impaired immune function , . Feelings of loneliness have been linked with mental and physical health outcomes . Indeed, loneliness correlates with higher levels of cortisol, the primary glucocorticoid in humans .
Cortisol levels rise during stress, hence cortisol is sometimes linked with negative affects .Also, those individuals with high cortisol secretions often have depressed moods . However, the association of negative effecte and cortisol is not straightforward. The main role for glucocorticoids (cortisol or corticosterone) in our bodies is to increase the energy available. For that our body triggers for instance the raise of blood glucose levels , 
Why has nature decided to make as vulnerable to loneliness?
The need to belong somewhere or to someone has an innate drive . When this requirement is not fulfilled, pain might be experienced in the form of loneliness.
From an evolutionary point of view, a loneliness mind state can be adaptive and functional . When a certain individual experiences loneliness in response of the loss of someone, that individual might be more prone to restore the gap made by that loss. These kind of people who do experience loneliness; have higher chances to survive and pass on their genes as their capability of survival is greater when compared to the rest of the community.
Indeed, experiencing transient levels of loneliness is not entirely negative and might even be positive as those might motivate to seek social contact. However, chronic levels of loneliness can lead to negative consequences such as sleep problems, cardiovascular disease and depression .
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