Mindful breathing and muscle contraction can be used to regulate the events that are happening in our body. Distance runners learn to regulate their breathing in order to slow the heart rate and get more oxygen to the muscles. Fighter pilots learn to control their breathing while simultaneously tensing their muscles in order to counteract the effect of G forces on the body. The reason this works has to do with the autonomic nervous system.

When we have overwhelming anxiety, we can use the following techniques to take control.
It is often difficult to distinguish between a panic attack and other medical events. (if chest pain is present, please call a nurse advice line immediately)
The sooner we intervene in a situation where anxiety is present in ourselves, the easier it is to get to a calm state. If one is already very anxious, these interventions will work, however it will be more difficult to lower the level of anxiety to a more manageable place.
  1. Rate the anxiety on a scale of 1-10, with ten meaning (I’m really anxious).
  2. Take any PRN medications that one may have to help with anxiety (follow doctor’s recommendations and be careful not to take too close to the last dose).
  3. If you have a biofeedback device such as a heart rate monitor or a blood pulse oximeter get it, and put that on the finger to check O2 stats and heart rate (what is Biofeedback?). If the heart rate is up, but the O2 seems to be fine, that’s likely a panic attack.
Lastly, let’s complete an intervention.
It is important to think about what has helped in the past. If you have found that one thing worked very well, try doing that again this time.
  1. The first exercise is a deep breathing exercise. Pull that up here: Basic Deep Breathing
  2. The second intervention is progressive muscle relaxation

  3. The third intervention is an integrated coping exercise which pulls from multiple approaches. (Click here for integrated coping)
If you already have mastered deep breathing, keep doing this type of breathing while you try Progressive Muscle Relaxation.
Periodically rate the anxiety, maybe every 15-20 minutes, or if noticeably calmer. 
A panic attack is the abrupt onset of intense fear or discomfort that reaches a peak within minutes and includes at least four of the following symptoms: Palpitations, pounding heart, or accelerated heart rate. Sweating. Trembling or shaking. Sensations of shortness of breath or smothering. 

Some people experience what is referred to as limited-symptom panic attacks, which are similar to full-blown panic attacks but consist of fewer than four symptoms.

Although anxiety is often accompanied by physical symptoms, such as a racing heart or knots in your stomach, what differentiates a panic attack from other anxiety symptoms is the intensity and duration of the symptoms. Panic attacks typically reach their peak level of intensity in 10 minutes or less and then begin to subside. Due to the intensity of the symptoms and their tendency to mimic those of heart disease, thyroid problems, breathing disorders, and other illnesses, people with panic disorder often make many visits to emergency rooms or doctors' offices, convinced they have a life-threatening issue. (Retrieved from: https://adaa.org/understanding-anxiety/panic-disorder-agoraphobia/symptoms)

Below is a video for extended relaxation/meditation.