The human body is an organic whole, although the skin is located on the surface of the human body, but is also a barometer of human health. As traditional Chinese medicine believes that “those who have it inside, must form it outside”, “those who have it outside must have it inside”, that is to say, skin diseases and the human body as a whole are closely related to each other, and can not be viewed independently. Therefore, other diseases can appear skin lesions, such as early tumors can be manifested as itchy skin, aspergillosis, erythema erythematosum or herpes zoster, etc.; intestinal polyps may be concomitant with freckle-like spots on the lips and mouth; diabetes mellitus can be accompanied by dry skin or prurigo, recurrent infections of the skin appearing as folliculitis, boils, or skin ulcers that are not easy to heal, etc., and if there are nerve damages, it is easy to occur blisters, blood blisters, flushing of the skin, sweat, secondary Eczema, skin infections, etc.; anemia can have pale nails, spatulate nails, itchy skin, etc.; aplastic anemia patients, the skin manifests as bleeding spots or large ecchymosis, blood blisters in the oral mucosa, epistaxis, bleeding gums, conjunctival hemorrhage, etc.; chronic hepatitis, cirrhosis of the liver can appear itchy skin, ecchymosis of the skin or bleeding gums, etc.. On the contrary, there are skin diseases maybe closely related to other diseases. For example, skin purpura can be seen in idiopathic thrombocytopenic purpura, leukemia, etc.; itchy skin can be seen in liver disease (especially obstructive), hepatitis C, renal failure, hypothyroidism, hyperthyroidism, malignant tumors, leukemia, diabetes mellitus, etc.; acute urticaria is often accompanied by gastrointestinal abnormalities: such as diarrhea, abdominal pain, or constipation, etc.; psoriasis is often accompanied by pharyngitis or tonsillitis; chloasma is often accompanied by breast hyperplasia, breast fibroids, ovarian cysts, or breast bleeding. fibromas, ovarian cysts or fibroids.