spiritual attack

[Old_Joe]

What does a spiritual attack feel like?

[Laudate_Dominum]

Spiritual attacks can vary across an extremely broad spectrum.
I suppose in most cases a spiritual attack may just be a general feeling of darkness and something like a weight pressing upon the soul. Spiritual attack can be accompanied by feelings of confusion, aridity in prayer, despairing thoughts, cynical thoughts, etc.. I'd say that most spiritual attacks manifest themselves in direct temptations to particular sins. For example common spiritual attacks may come rolled up in temptations to impurity, anger, unbelief, despair and pride.
Basically things that are directly contrary to gifts and fruits of the Holy Spirit. The Spirit of God living within a person is manifested through purity, peace, joy, faith, humily, etc..
There are extraordinary spiritual attacks, which are quite rare, but these can even include physical phenomenon. Extreme cases are those such as in the lives of saints like St. Jean Vianney and St. Padre Pio in which demons physically assault the person in an entirely tangible way.
Even in the less extraordinary forms there can be physical sensations involved. Demonic oppression can include a physical feeling of pressure to the head which accompanies the general state of confusion and darkness.
Through prayer or deliverance of some kind one may feel physically as though the weight on the mind, or some cloud of darkness has been dispelled.
Similarly the experience of God's Presence and Spirit operative in a person may include physical sensations. One can "feel" joy and love like a sweet fire in their heart.

While there is some value in stressing that what one may think is a spiritual attack might just be emotional and/or psychological things. Such as depression or anxiety due to situations in one's life or a chemical imbalance, I would say that this can be true and include a spiritual attack because the forces of darkness will tend to prey upon a persons dispositional weaknesses.

Anyway, in my unprofessional opinion there are a variety of physical sensations that can accompany demonic attack and oppression. Among these I would list: the feeling of weight or pressure upon the mind; a feeling of confusion and/or darkness in the mind; a feeling of emptiness or anxiety in one's center or bosom; sometimes peculiar dart like sensations in the abdomen; unusual gastrointestinal sensations; a feeling of dread, fear or disgust caused by the perception of the presence of a demonic being (or beings); etc..

Another common "feeling" associated with the presence of demonic activity in a persons soul is an aversion to holy things. For example a crucifix or image of Our Lady might evoke feelings of anger or a general aversion by the person caught in the grasp of the demonic. And there might be a great difficulty in focusing one's thoughts on holy things or keeping them fixed on things that are good and of God.
There may be a morbid attraction to unholy and undignified things, or things that are simply against goodness and holiness.

Discerning whether a particular thing is simply a habituated vice, a psychological defect, or an explicit demonic attack is not necessarily easy all the time. Perhaps bringing it before Christ in adoration or something may shed light on the cause (it might be all of the above).
But in my experience there really isn't much good that can come from a preoccupation with the demonic. It is best to maintain a certain simplicity with regards to temptations and sensations and not entertain an unhealthy curiosity.