Physical effects of panic attacks include respiratory and cardiovascular which can then have mental manifestations...
Respiratory Effects of Panic Attacks
One of the scariest effects of a panic attack is the fear of suffocating or smothering. It is very common during a panic attack to feel tightness in the chest and throat. I’m sure everyone can relate to some fear of losing control of your breathing. From personal experience, anxiety grows from the fear that your breathing itself would cease and you would be unable to recover.
Can a panic attack stop our breathing? No.
A panic attack is associated with an increase in the speed and depth of breathing. This has obvious importance for the defense of the body since the tissues need to get more oxygen to prepare for action. The feelings produced by this increase in breathing, however, can include breathlessness, hyperventilation, sensations of choking or smothering, and even pains or tightness in the chest. The real problem is that these sensations are alien to us, and they feel unnatural.