Sirsasana is nicknamed “king” of all the asanas.  The name comes from the Sanskrit words Shirsha (शीर्ष, Śīrṣa) meaning “head” and Asana (आसन, Āsana) meaning “posture” or “seat”.  It is one of the most important asanas in yoga. It revitalizes the entire body and stimulates the mind.

Here is a link to a nice step-by-step explanation of how to perform a head stand: https://www.doyouyoga.com/a-beginners-guide-to-headstands-14010/

Here is a beginners video for how to do the head stand: https://www.youtube.com/watch?v=iZ4Ryi-xHvs  

Regular practice of sirsasana makes healthy pure blood flow through the brain cells. This rejuvenates them so that thinking power increases and thoughts become clearer. Headstand stimulates the nervous system, increasing mental alertness and clarity. It is a centering, calming and soothing pose. People suffering from loss of sleep, memory and vitality have recovered by the regular practice of this asana.

By reversing the pull of gravity on the organs, especially the intestines, it helps to cleanse them and overcome problems of the liver, kidneys, stomach, intestines and reproductive system. Headstand increases gastric fire and produces heat in the body. When done properly, headstand helps the spine become properly aligned, improving posture, facilitating good breathing and reducing muscular stress. The weight of the abdominal organs on the diaphragm encourages deep breathing, which gently massages the internal organs. Sirsasana is used to treat asthma, hay fever, diabetes, headaches, anxiety and menopausal imbalance.

Time spent upside down everyday, especially in sarvangasana and sirsasana, is one of the best things you could possibly do for yourself. These poses bring health and vitality to the body while calming and soothing the mind and spirit.