半夏
The Processing of 半夏
Origin
The dry tuber of perennial herbaceous plant Pinellia ternata (Thunb.) Breit. of family Araceae.
Location
Sichuan, Hubei and Shandong provinces in China.
Harvest
Collected in summer and autumn.
The actual smell and taste
Light smell, acrid and spicy, tongue-numbed taste stimulating the throat.
Best quality
White, firm, powder-like, old.
Processing
Processed with ginger juice and alum.
The Effect of 半夏
Property
Pungent, warm, toxic; lung, spleen and stomach meridians entered.
Actions
Dry dampness and resolve phlegm, check adverse rise of qi and stop vomiting, relieve stuffiness and dissipate nodulation, resolve swelling and alleviate pain externally.
Indications
A. Damp-phlegm, cold-phlegm
This herb takes the action of drying according to its pungent and warm property. It is good at drying dampness to resolve Phlegm and turbidity. It can also relieve cough. It serves as the key herb of drying dampness, resolving phlegm, warming and resolving cold-phlegm. It especially excels at treating damp-phlegm of Zang and Fu-organ. For damp-phlegm obstruction of lung, obstruction of lung qi, cough and adverse qi flow, profuse white expectoration, it is usually combined with qi-regulating, damp-drying and phlegm-resolving herbs to dry dampness, resolve phlegm, regulate qi and harmonize the middle. For instance it is combined with Chen Pi, Fu Ling and Gan Cao in Er Chen Tang from Tai Ping Hui Min He Ji Ju Fang. For cough and dyspnea due to cold retained fluid and clear profuse phlegm, it is combined with lung-warming and retained fluid-resolving herbs. For instance it is combined with Gan Jiang and Xi Xin in Xiao Qing Long Tang from Shang Han Lun. For headache, vertigo even vomiting of phlegm and sputum caused by damp-phlegm invasion the upper clear yang, it is combined with damp-drying herbs and analgesics. For instance it is combined with Tian Ma and Bai Zhu in Ban Xia Bai Zhu Tian Ma Tang from Yi Xue Xin Wu. For insomnia due to excessive internal phlegm and retained fluid and disharmony of stomach qi, it is combined with Shu Mi to resolve phlegm, harmonize stomach and calm down the mind, for instance the Ban Xia Shu Mi Tang from Ling Shu (Spiritual Pivot).
B. Nausea, vomiting, hiccup and belching
It can both dry dampness to resolve phlegm and check averse rise of qi to harmonize stomach. So it has excellent action of relieving vomiting as a key herb. It is used in combination according to the syndrome of vomiting caused by all kinds of reasons. It is especially indicated for vomiting resulted from phlegm, retained fluid and stomach cold because it is warm and dry in property and good at resolving phlegm. It is combined with Sheng Jiang to enhance the actions of resolving phlegm, dispelling cold and stopping vomiting in Xiao Ban Xia Tang from Jin Kui Yao Lue, For vomiting caused by stomach heat, it is combined with stomach-clearing and vomiting-stopping herbs such as Huang Lian, Lu Gen and Zhu Ru. For vomiting due to stomach deficiency and adverse rise of qi, it is combined with spleen and stomach tonics. For instance it is combined with Ren Shen and Bai Mi to tonify and check adverse rise of qi in Da Ban Xia Tang from Jin Kui Yao Lue. For vomiting due to stomach yin deficiency, it is combined with yin tonics such as Shi Hu and Mai Dong. For instance it is combined with Mai Dong, etc. in Mai Men Dong Tang from Jin Kui Yao Lue. This herb is also indicated for vomiting during pregnancy. For instance, for morning sickness and vomiting due to stomach deficiency and cold retained fluid, it is combined with Gan Jiang and Ren Shen in Gan Jiang Ren Shen Ban Xia Wan from Jin Kui Yao Lue.
C. Epigastric stuffiness, thoracic accumulation, plum-stone syndrome
This herb is capable of drying dampness, and resolving phlegm and stuffiness. For epigastric stuffiness caused by phlegm-heat obstruction, it is combined with Gan Jiang, Huang Lian and Huang Qin in Ban Xia Xie Xin Tang from Shang Han Lun. And in Shang Han Lun, it is also combined with Gua Lou and Huang Lian in Xiao Xian Xiong Tang. For plum-stone syndrome due to qi stagnation and phlegm congealing, it is combined with Zi Su, Hou Po and Fu Ling to move qi, relieve depression, resolve phlegm and dissipate nodulation in Ban Xia Hou Po Tang from Jin Kui Yao Lue.
D. Goiter, tumor, phlegm nodule, abscess and deep rooted carbuncle
This herb is capable of resolving phlegm and dissipating nodulation by internal taking and resolving swelling and alleviating pain by external use. For the first stage of sore and abscess, it is ground into powder or freshly smashed, applied externally. For goiter, tumor and phlegm nodule, it is combined with phlegm-resolving and hardness-softening herbs, for instance with Kun Bu, Hai Zao and Bei Mu in Hai Zao Yu Hu Tang from Wai Ke Zheng Zong (Orthodox Manual of External Medicine).
For scrofula, it is made powder with Sheng Ban Xia and Tian Nan Xing and mixed with ginger juice recorded in Yi Zhong Shuo Yue (Discussions of Medical Doctors).
Dosage and Administrations
Decoct 3~10g. Generally it is processed. Processed Ban Xia is named by Jiang Ban Xia and Fa Ban Xia and so on. Basically Jiang Ban Xia is good at checking adverse rising of qi and relieving vomiting, Fa Ban Xia good at drying dampness with mildly warm nature, Qing Shui Ban Xia (Qing Ban Xia) good at resolving phlegm. Ban Xia Qu can resolve phlegm and relieve cough and has the action of promoting digestion and removing food stagnation. When Ban Xia is processed with Zhu Li, the warm and dry property is weakened and the action of resolving phlegm is enhanced. It can clear and resolve heat-phlegm and is indicated for the syndrome of heat-phlegm and wind-phlegm. Unprocessed Ban Xia is mostly used externally.
Cautions
Contraindicated to Wu Tou. Use with cautions during gestation.