Q: How can a person strengthen his immune system according to Kabbalah?
A: The immune system in the body corresponds to the sefirah of Hod. To strengthen the sefirah of Hod, it is advisable to begin each day with the "Modeh ani" (Thanksgiving) prayer with intense concentration. Hod means the power to thank G-d always, in simple sincerity, as well as thanking all people who do you good. These guidelines should be put into practice.