The causes of pruritus often include dry skin, psychoneurologic factors, systemic diseases, endocrine disorders, drug factors, environmental factors and so on. 1. Dry skin: dry skin is the most common cause of pruritus. Elderly skin aging, sebum secretion reduction, air is too dry, frequent bathing, frequent use of alkaline toiletries, etc. are easy to cause dry skin, which in turn induces pruritus. 2. Neuropsychiatric factors: long-term mental tension, anxiety, excitement, fear, etc. can cause itching. 3. Systemic diseases: this factor is usually divided into systemic diseases and other systemic diseases. Common such as kidney disease, uremia, hyperthyroidism, diabetes mellitus, hepatopathy syndrome, etc. can easily cause systemic itching; and other systemic diseases caused by itching common such as vaginal trichomoniasis, vaginal fungal infections, gonorrhea, etc. caused by vulvovaginal itching; hemorrhoids, fissures, etc. caused by perianal itching. 4. Endocrine disorders: changes in human hormones can also cause itching, such as itching during pregnancy or menstruation of women’s skin. 5. Drugs: morphine, angiotensin-converting enzyme inhibitors, analgesics, vitamin B and other drugs can also cause itching. 6. Environmental factors: sudden changes in temperature, frequent contact with irritants (alkaline detergents, disinfectants, fuel, etc.), close-fitting clothes, chemical fiber products can also cause secondary itching. It is recommended that patients identify the cause of the disease in a timely manner and receive targeted treatment as prescribed by the doctor.