English: Common rush

Chinese: 灯心草

Parts used: Dried stem pith

TCM category: Herbs that drain Dampness

TCM nature: Cold

TCM taste(s): Sweet

Organ affinity: Heart Lung Small intestine

Scientific name: Juncus effusus

Use of Deng Xin Cao (common rush) in TCM

Please note that you should never self-prescribe TCM ingredients. A TCM ingredient is almost never eaten on its own but as part of a formula containing several ingredients that act together. Please consult a professional TCM practitioner, they will be best able to guide you.

Preparation: Cut the stems, dry them, take out the stem pith, straighten them and tie them into small handfuls

Dosage: 2 to 3 grams

Main actions according to TCM*: Diuretic, promotes urination. Clears urinary tract infections.

Primary conditions or symptoms for which Deng Xin Cao may be prescribed by TCM doctors*: Urinary tract infection Sore throat Oliguria Mouth ulcers Tongue ulcers Scanty urination Insomnia Restlessness

Contraindications*: Not for individuals with Spleen and Stomach Coldness and Deficiency

Common TCM formulas in which Deng Xin Cao is used*

Ba Zheng San

Source date: 1107 AD

Number of ingredients: 9 herbs

Formula key actions: Clears Heat and Fire. Promotes urination. Unblocks painful urinary dribbling.

Conditions targeted*: GlomerulonephritisCystitis and others

Deng Xin Cao is an envoy ingredient in Ba Zheng San. This means that it directs the formula towards certain area of the body and/or harmonizes the actions of other ingredients.

In Ba Zheng San, Deng Xin Cao guides Heat downward as one of the envoys. 

Read more about Ba Zheng San

Key TCM concepts behind Deng Xin Cao's properties

In Traditional Chinese Medicine (TCM), Deng Xin Cao belongs to the 'Herbs that drain Dampness' category. These herbs are typically diuretics, meaning that they promotes the increased production of urine in order to remove Dampness that has accumulated in the body. According to TCM Dampness accumulates first in the lower limbs, causing edema and impaired movement. From there, if unchecked, it can move upward and impair digestion and eventually the respiratory system.

Furthermore Deng Xin Cao is Cold in nature. This means that Deng Xin Cao typically helps people who have too much 'Heat' in their body. Balance between Yin and Yang is a key health concept in TCM. Those who have too much Heat in their body are said to either have a Yang Excess (because Yang is Hot in nature) or a Yin deficiency (Yin is Cold in Nature). Depending on your condition Deng Xin Cao can help restore a harmonious balance between Yin and Yang.

Deng Xin Cao also tastes Sweet. The so-called 'Five Phases' theory in Chinese Medicine states that the taste of TCM ingredients is a key determinant of their action in the body. Sweet ingredients like Deng Xin Cao tends to slow down acute reactions and detoxify the body. They also have a tonic effect because they replenish Qi and Blood.

The tastes of ingredients in TCM also determine what Organs and Meridians they target. As such Deng Xin Cao is thought to target the Heart, the Lung and the Small intestine. In addition to regulating Blood flow, in TCM the Heart is believed to be the store of the 'Mind' which basically refers to someone's vitality. In addition to performing respiration, the Lungs are thought in TCM to be a key part of the production chain for Qi and the Body Fluids that nourish the body. Like the Stomach, the Small Intestine has a digestive role, extracting the "pure" part of what we injest to the Spleen and the "impure" down to the Large Intestine.