Dan Shen

'Invigorates Blood and dispels stasis' is Dan Shen's primary and most celebrated action. It means this herb actively promotes blood circulation and breaks up stagnant blood that has accumulated in the body. Blood stasis (stuck or sluggish blood flow) can cause sharp, fixed, stabbing pains in the chest or abdomen, formation of masses, or darkened complexion and tongue. Dan Shen is considered one of the most important herbs in the entire Materia Medica for treating blood stasis conditions. A classical saying states that "a single herb Dan Shen has the function of the whole Four-Substance Decoction" (一味丹参，功同四物), highlighting its versatility in treating blood disorders.

'Promotes menstruation and alleviates pain' means Dan Shen helps restore normal menstrual flow when periods are irregular, painful, absent, or scanty due to blood stasis in the uterus. It is widely regarded as a key gynaecological herb. The pain-relieving action extends beyond menstrual pain to chest pain, epigastric pain, and joint pain caused by blood stasis and Heat.

'Clears Heat from the Heart and relieves restlessness' refers to Dan Shen's ability to calm the mind when pathogenic Heat has entered the deeper levels of the body (the nutritive or Blood level). In febrile diseases where Heat disturbs the Heart, symptoms such as high fever worse at night, delirium, irritability, and insomnia may appear. Dan Shen's bitter and cool nature allows it to enter the Heart channel and clear this Heat while calming the spirit. For everyday restlessness and insomnia from milder Heat patterns, it is often combined with calming herbs like Suan Zao Ren (sour jujube seed).

'Cools the Blood and reduces swelling' means that when Heat toxins cause painful sores, abscesses, or skin lesions, Dan Shen can cool the Blood and disperse the stagnation that feeds the swelling. It is particularly noted for early-stage breast abscesses and hot, swollen skin conditions.

'Nourishes the Blood and calms the spirit' is a secondary action. While Dan Shen primarily moves Blood, it also has a gentle nourishing quality. When Blood fails to nourish the Heart, symptoms like palpitations, anxiety, and poor sleep can arise. Dan Shen helps generate new blood while calming the spirit, making it useful for insomnia and heart palpitations, especially when combined with tonifying herbs.