Blood is mainly responsible for nourishing and keeping the body moist. Internally, it circulates to the organs, and externally, it flows to skin, flesh, bones and muscles. Its detailed functions are as follows: 1. Providing nutrients for organs, tissues and meridiansWith sufficient nourishment from the blood, and tissues can function normally resulting in a healthy glow in the skin, cheeks, and hair. and bones also rely on blood nourishment to remain strong and healthy. 2. Maintaining healthy body movement and sensationThe Huang Di Nei Jing, a famous Chinese medicine text from the Han dynasty, says, "Having received sufficient blood, the liver can support healthy eyesight. Having received sufficient blood, feet can walk. Having received sufficient blood, the palm can grasp hold of things. Having received sufficient blood, the fingers can pick up things." This illustrates blood's importance in healthy muscle movement and sensation. If blood is deficient, dizziness, vertigo, ringing in the ears (tinnitus) or limb weakness can occur. 3. Aiding the mind and mental activitiesA good blood supply is also important for mental health. With sufficient blood nourishment, a clear mind, good spirit, fast thought processes and swift reaction times are possible. On the other hand, deficiency of blood leads to poor memory and insomnia and in serious cases causes mental disorders and psychiatric diseases.