Therapeutic role of yoga in hypertension

Table 2 Effect of yoga practices on hypertension and their mechanism of action

Yoga Practice	Effect on hypertension	Mechanism of action
Shatkriya (Cleansing practices)
Trataka kriya	Significant reduction in BP and HR in patients with primary hypertension[8]	Induces calmness similar to a mental state during meditation[8]
Neti kriya	Clear up the head and neck region producing a sense of lightness[6]; Beneficial in reducing anxiety and depression	Reduce toxic accumulation in head and neck region
Sharir Sanchalana (Warm-up practices)
Sharir Sanchalana	Warm-up exercises prepare the body for the practice of asana	Removes stiffness in the muscles and joints; Improve blood circulation
Surya Namaskara (Sun salutations)
Slow practice of Surya Namaskara	Recommended for pre and stage I hypertension[10]	Produce psychosomatic harmony[6]
Asana (Yoga postures)
Asana practiced with awareness and breath synchronization	Prevent and attenuate the age-related deterioration of physical health, muscular strength, and flexibility[36]; Capable of bringing about the stability of body and mind; Improves the flow of vital energy through the body, resulting in a positive sense of well-being; Preparatory practice for meditation that fosters a quieting of the mind	Holding yoga postures for a few seconds build strength by using body weight for resistance, which in turn slows the onset of sarcopenia[36]; Mental relaxation and a state of “restful awareness”; Changes the long-held patterns of feelings and emotions; Exert controlled pressure on the kidneys and the adrenals, which regulates BP through secretions of hormones like renin, angiotensin, adrenaline, etc.[31]
Restorative Yoga	More effective with significantly greater reductions in BP and HR as compared to stretching[11]	Facilitates stretching, provides support, and induces relaxation. Releases habitual stress patterns that are stored in the body as areas of tension
Shavasana (corpse pose) with breath awareness	Effective in BP reduction[12]	Reduction in the load on the heart by blunting the sympathetic response along with an enhanced parasympathetic activity[12]; Allows the body and mind to integrate through mindful stillness
Forward bending poses	“Head-down” postures confer stress-reducing, calming, and mind-quietening benefits	Forward bends with head supported brings a sense of calm
Backward bending poses	Elevate low mood and have energizing effect	Chest opening poses that allow expansive inhalation; Stimulate the heart chakra associated with emotions and balance
Twisting postures	Release tension, and energize; Helps in de-stressing, relaxing, and unwinding	Relieve spinal stiffness and clear emotional blockages
Meditative postures	Maintain a steady comfortable position for a long time without conscious effort; Improve concentration and peace of mind	The heart rate and the breath slow down, which lowers the BP. Enhance feelings of being grounded, centred, and balanced
Pranayama (Regulated breathing practices)
Slow-paced pranayama	A modest reduction in BP[14]	Optimally balances sympathovagal stress response [27]; Baroreceptor sensitivity can be enhanced significantly by slow breathing[18]
Deep slow abdominal breathing	Effective in reduction of systolic BP	Improve vagal tone, increase parasympathetic dominance, and decrease sympathetic discharges[30]
Sukha pranayama (Easy, comfortable breathing)	A significant reduction in Heart rate, systolic pressure, pulse pressure, and mean arterial pressure[16]	Normalization of autonomic cardiovascular rhythms as a result of increased vagal modulation and/or decreased sympathetic activity and improved baroreflex sensitivity[16]
Immediate Effect of Nadi shodhana pranayama (Alternate nostril breathing)	Reduce the BP and HR[17]	Activating the parasympathetic nervous system and enhancing healthy cardiovascular functioning[17]
Slow pace (respiratory rate 6/min) bhastrika pranayama (Bellows breath)	Reduction in systolic and diastolic BP[18]	Enhanced parasympathetic activity[18]
Chandra nadi pranayama (Left unilateral forced nostril breathing)	An immediate decrease in cardiovascular parameters with the decrease in HR, systolic pressure, and pulse pressure[19]	Normalization of autonomic cardiovascular rhythms with increased vagal modulation and/or decreased sympathetic activity along with improvement in baroreflex sensitivity[19]
Bhramari pranayama (Humming breath)	Immediate positive effect on reducing the systolic BP[20]	Parasympathetic dominance[20]
Ujjayi pranayama (Ocean breath) without breath retention or bandhas	Significantly decreases stress-induced changes in cardiorespiratory parameters and decreases BP[15]	Shift autonomic nervous control toward the parasympathetic side[15]; Exerts gentle pressure on the carotid sinuses that regulates BP through homeostatic mechanisms
Sheetali pranayama (Cooling breath)	The immediate effect: reduce the systolic and diastolic BP in hypertensive patients[21]	Decreasing the sympathetic activity[21]
Pranava pranayama/AUM chanting	Five min of AUM chanting reduces systolic and diastolic BP[13]; Reduces depression, anxiety, and stress[24]; Improves quality of sleep[24]; Promotes relaxation, and provides calmness	Improvement in baroreflex sensitivity resulting in the normalizing of autonomic cardiovascular rhythms[24]
Mudra (Subtle gestures)
Brahma mudra (Divine spiritual gesture)	Induces a sense of relaxation and reinvigoration in the head and neck region that reduces stress[6]	Cultivates psychosomatic harmony, induces relaxation, reduces stress
Apaan vayu mudra (Mudra of the heart)	Reduction in systolic and diastolic BP	The finger position sensitizes nerves in the palm and wrist area resulting in a systemic effect on the cardiovascular system
Shanmukhi mudra (Closing the 7 gates)	Produces a sense of inner calm[6]	This mudra encourages ‘pratyahara’, which means withdrawing the mind inwards by blocking some of the sensory distractions of the surroundings
Gyan mudra (Mudra of wisdom)	Reduces mental stress, indicated in hypertension	Deepens awareness; Enhances meditation experience; Regulates the fire and air elements in the body
Meditation
Formal meditation
Concentration meditation	Significant decrease in the HR and systolic and diastolic BP[22]; Reduces stress and anxiety; Induces relaxation	Modulates the physiological response to stress via neurohumoral activation[22]; Decreases the arterial tone and the peripheral resistance
Mindfulness Meditation (Non-judgmental awareness of the present moment with kindness, acceptance, and curiosity)	Significant effect on reducing systolic and diastolic BP in patients with hypertension[23]	Focus on the moment with “acceptance” and “non-criticism” helps in regulating the emotional state. Emotional stability relieves the somatization symptoms and the BP is reduced[23]
Informal meditation
Mindfulness	Helps to cope face day-to-day challenges and stressful situations	Serves as a ‘micro-meditation’ technique for quick stress relief
Yoga nidra (Yogic sleep or effortless relaxation)
Yoga nidra	Reduces systolic and diastolic BP[29]; Reduces depression, anxiety, and stress[24]; Improves quality of sleep[24]	Improve autonomic functions[24,29]; Influence the brain’s electrical rhythms[29]

BP: Blood pressure; HR: Heart rate.