The word "Brahmari" comes from the Sanskrit word which 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. The practice of Brahmari breathing (Bumble Bee Breath) calms the mind and reduces the fight or flight stress response. It reduces cerebral tension, anger, anxiety, and insomnia, while aiding in lowering blood pressure. This pranayama is very effective in speeding up the healing of body tissues and may be practiced after surgeries. It has a calming effect on entire nervous system, especially it stimulates the parasympathetic nervous system, which induces muscular relaxation and is very effective in stress management. So Brahmari is very effective for relaxation of body and mind.
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. Or you could always play it off like you’re humming to your favorite song to yourself!
Practice Brahmari Breathing:
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 Bumble 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.