Hemp is a perennial herb, distributed in most parts of the country. Its dried tuber, also known as gastrodia elata, is a commonly used and expensive Chinese medicine, which is often used in clinic for headache, dizziness, numbness of limbs, infantile convulsion, epilepsy, convulsion, tetanus and other diseases. Children can eat gastrodia elata. Usage and dosage: 5 5~ 10/0g per day. Decoct soup, soak in wine, and serve in dishes. Take it after grinding, each time1~1.5g. Adverse reactions Gastrodia elata has obvious effects on headache and dizziness caused by hyperactivity of liver yang, so it is often taken as a tonic. At the sight of dizziness, regardless of physical deficiency and excess, qi and blood rise and fall, gastrodia elata is used indiscriminately, and the result may be the same adverse reactions as the above patients. The common adverse reactions of taking Gastrodia elata include dizziness, nausea, chest tightness, skin papules with itching, etc., and some people may have facial or systemic edema and even hair loss. Not only will this kind of reaction occur when gastrodia elata is used alone, but some people will also have allergic symptoms to gastrodia elata after taking decoction containing gastrodia elata, such as Banxia Baizhu Tianma Decoction, and Chinese patent medicines such as Tianma pills and gastrodia mellea sugar-coated tablets. The ancients had long known the side effects or contraindications of Gastrodia elata. For example, "Compendium of Materia Medica" says: "After taking Gastrodia elata for a long time, red lead is emitted all over." "Ben Jing Feng Yuan" also says: "Although Gastrodia elata is not dry, after all, if there is no wind due to blood deficiency, people with fire, headache and dry mouth should not be misused." Wu Yiluo, a famous doctor in the Qing Dynasty, even bluntly said: "People with less blood failure and non-real stroke should not use it." Modern pharmacological experiments show that gastrodia elata has certain toxic and side effects, the poisoning dose of gastrodia elata is more than 40 grams, and the poisoning incubation period is1~ 6 hours. Precautions: When using Gastrodia elata, "the medicine is not right" is one of the important reasons causing adverse reactions. Therefore, we should pay attention to the following points when using Gastrodia elata: 1. All patients should use Gastrodia elata with caution when they see fluid deficiency, blood deficiency, yin deficiency, etc. Gastrodia elata-plant in its original state 2. Pay attention to compatibility and application. "Materia Medica Yanyi" has a description that "Gastrodia elata must be assisted by other drugs, and then see its merits". Ancient and modern physicians rarely use gastrodia elata singly, but mostly use drugs according to different disease syndromes. Such as: Banxia Baizhu Tianma Decoction, Tianma Gouteng Drink, Tianma Pill, etc. Clinically, the effect of gastrodia elata alone is not good or the effect is uncertain. 3. Even in the case of hyperactivity of liver yang and phlegm blocking meridians, gastrodia elata should be carefully examined, and the pathogenesis should be grasped, so as to achieve good therapeutic effect. 4. Gastrodia elata should not be fried for a long time. The main component of gastrodia elata is gastrodin, which is extremely volatile when exposed to heat. Gastrodia elata and other drugs will lose the effective components of sedation and analgesia due to heat. Therefore, it is best to moisten gastrodia elata with a small amount of water first, cut it into thin slices after softening, dry it in the air or dry it and grind it into powder, and take it with the decoction, or grind it into pills and take it in powder. 5. When using single gastrodia elata or gastrodia elata preparation, if dizziness, chest tightness, shortness of breath, nausea and vomiting, rapid heartbeat and breathing, itchy skin, etc. occur, stop taking the medicine immediately, and those with severe symptoms should go to the hospital in time. 6. Gastrodia elata can't be used with Yufeng Grass Root, otherwise it will cause intestinal knot.