Anxiety is commonly associated with short, tight upper-chest breathing, says Timothy McCall, MD. Relaxation, on the other hand, comes with slower breaths that originate from the diaphragm. "Lengthening exhalation relative to inhalation reduces the 'fight or flight' impulse and maintains a healthy level of carbon dioxide in the blood, which helps you relax," he says.
For anxiety, McCall recommends a pranayama (breathwork) technique known as brahmari, Sanskrit word that means "bee." The practice is named for the humming sound that bees make. The sound is soothing for a spinning mind, and the practice lengthens the exhalation without excessive strain.
Brahmari can be used as a regular daily practice to encourage relaxation or as an on-the-spot remedy. Because of the buzzing sound, however, it's the kind of practice that you might not choose to do in public. If you are out somewhere and experiencing anxiety, look for a place that's relatively private, like a bathroom or your parked car.
To practice Brahmari Pranayama, sit comfortably, with the back tall and shoulders relaxed. Start by taking a few natural breaths, and close your eyes (as long as closing them doesn't produce more anxiety). Then, keeping the lips lightly sealed, inhale through the nostrils. Exhaling, make the sound of the letter M, essentially a humming sound. Sustain the sound until you need to inhale. Then repeat: Inhale through the nose, then hum like a buzzing bee as you exhale. Continue by inhaling as needed and exhaling with this sound for several minutes. You can practice as long as it feels good.
The longer you sustain the humming exhalation, the more relaxing the Bee Breath is likely to be—but forcing the breath beyond your capacity can have the reverse effect, causing even more stress. So don't force yourself to maintain any particular speed. Inhale whenever necessary, and let the buzzing sound last as long as it is comfortable. Finally, spend a few breaths sitting quietly and noticing whether there are any changes in your breath or mood."