There are many skin diseases with itching symptoms have not much itching during the day, the night will be obvious or significantly aggravated, Chinese medicine consider two causes: 1, Yin and blood deficiency: Chinese medicine is called blood deficiency, is the production of wind, Yin and blood deficiency is prone to wind dryness, resulting in itchy skin, because the itching caused by blood deficiency and wind, treated with drugs to clear heat, cool the blood and dispel wind; 2, blood heat: all pain and itching All sores belong to fire, fire-heat is more obvious, and this condition of blood-heat can also lead to increased itching of the skin. Because it is caused by pure blood heat, the use of drugs to clear heat, cool the blood and detoxify the toxin will allow the aggravation of itching at night to be significantly improved.