Stop the practice if you feel any discomfort in the form of pain, dizziness, fainting and so on.
Kapalbhati should not be done by those people who suffer from ailments such as high blood pressure, vertigo, hernia and so forth. Be discreet.
The benefits are very similar to bhastrika pranayama. Briefly the main benefits are as follows:
Digestion: massages and improves the functioning of the digestive organs.
Brain: clears the frontal lobe of the brain by speeding up the blood flow. At a more subtle level it also stimulates pranic flow in the same region.
Respiration: kapalbhati cleans out the lungs. It improves their elasticity and makes oxygen-carbon dioxide exchange more efficient. It should certainly be practised by those people who suffer from respiratory ailments such as bronchitis, tuberculosis, etc. Those who suffer from asthma and emphysema will, from habit and necessity, utilize forceful exhalation to expel air from the lungs. This tends to induce severe muscular tiredness. Kapalbhati, practised at times other than during an attack, may be useful in making respiratory muscles stronger, as well as improving the general tone of the lungs.
Alertness: kapalbhati wakes up the mind. So, if you have a lot of mental work to complete, yet feel tired, we suggest that you energize the mind with a few rounds of kapalbhati.
Kapalbhati is one of the best preparatory techniques for meditative practice. It empties the mind of thoughts, emotional feelings and excessive visions. It induces a tranquil, receptive state of mind. From our experience, the ideal practice to follow after kapalbhati is chidakasha dharana.
Reversal of nerve reflexes
Normal breathing is characterized by active contraction of only the inspiratory muscles, such as the diaphragm and the external intercostals; expiration occurs passively on the cessation of this contraction of the internal intercostals. Kapalbhati reverses this process: exhalation is active and inhalation is passive. This induces a reversal in the flow of the nerve impulses to and from the brain, bringing about stimulation and awakening of the brain centres. This is one reason for the brain-stimulating effect of kapalbhati, at least on a physiological basis. It should be noted that the expiratory muscles usually only come into action when there is obstruction to respiration, or when there is a great need of extra oxygen in the system.