Anyone who tells you there is a way to stop a panic attack in five minutes or under without any preparation is lying. However, if you take the time out to equip yourself with mental exercises, knowledge and physical processes to carry out in an anxiety attack situation then it is definitely possible to go from panic to peaceful in no time at all.
Firstly you need to understand why panic occurs in the first place. Presumably you already know that through irrational thought you have made yourself phobic of something, or caused yourself to become very nervous in a certain situation. Much of this you can actually blame on a certain area of your brain, the amygdala, which associates this worry with a real threat to your survival. While rationally you know the situation won't kill you, your brain thinks it will and it begins preparing your body to either run as fast as it can or stay and fight the threat. This process is known as the fight or flight response.
Along with the fight or flight response comes a rush of the hormone adrenaline, which makes your heart beat faster, your muscles contract and your respiratory system work harder to get oxygen to the muscles that will need it when you're running or fighting. Since modern day situations rarely require such high levels of exercise we flood our bodies with oxygen and as a result our blood pH level rises. When this happens our blood vessels constrict, blood flow to the brain is inhibited and we start to feel those classic symptoms of not just anxiety but a full blown panic attack: dizziness, tightness in the chest, an inability to breathe and complete overwhelming.
So how to stop it? Your first step should be, while you are calm, to begin therapy sessions with a trained professional or attend a cognitive behavioral group. Without this you could never get to the bottom of why your panic attacks happen and you could be experiencing panic attacks forever. CBT and counseling specialists will also arm you with your own methods for keeping calm.
Learning some breathing exercises can help immensely in stopping panic attacks. For instance, before you approach the situation you should breathe in slowly for the count of three and then out even slower for the count of four. 'Three' and 'four' don't necessarily mean seconds, but just however slow you feel you can breathe in and out. Try to extend this time the more breaths you take and you should see yourself becoming calmer.
Alternatively, if you find yourself hyperventilating then you should either try holding your breath for as long as you can, perhaps three or four times, or breathe out to the bottom of your breath slowly, breathe in to the top of your breath slowly and then breathe out to the bottom of your breath again but this time fast and hard. Hold your breath at the bottom here for as long as you can and continue breathing normally.
While panic attacks can only truly be combated by facing the one thing we are afraid of: whatever is causing the panic attacks, there are some ways to ease the effects of a panic attack when they come. In time, with therapy or cognitive behavioral therapy you should see a marked difference in your ability to cope with certain situations.