Difficult and complicated disease refers to the general term for diseases that are difficult to diagnose, or tricky to treat, such as rheumatoid arthritis, vitiligo, cancer, Parkinson’s disease and so on. 1. Rheumatoid arthritis: a chronic inflammatory systemic disease of the joints of which the cause is not clear, manifested by deformation and deformity of many joints of the hands and feet, which can lead to the loss of joint function in severe cases, and the current treatment is mainly based on anti-inflammatory, analgesic and hormonal therapy, which can not cure rheumatoid arthritis completely. 2. Vitiligo: an acquired pigmented skin disease, manifested as local or large areas of the skin and mucous membrane pigmentation loss, can cause severe uveitis, the cause is unclear, the current general use of hormone therapy, phototherapy, or oral vitamin D3 derivatives to assist in the treatment of vitiligo, can improve the severity of vitiligo. 3. cancer: cancer is also commonly known as malignant tumors, such as liver cancer, lung cancer, stomach cancer, etc., the cause of cancer lies in the uncontrolled differentiation of cancer cells, infiltration of the human body, the current treatment of cancer is mainly based on surgery, with radiotherapy chemotherapy or immune treatment, but the cancer can not be completely cured at present. 4. Parkinson’s disease: also known as tremor paralysis, is a kind of disease that has a big impact on the patient’s mobility and the central nervous system, the current research is mainly due to the lack of dopamine in the brain cells, but at present, Parkinson’s disease can only be controlled, and cannot be cured. 5. Various hereditary metabolic diseases, the diagnosis is more difficult, the treatment of most of the no effective way, part can only alleviate the symptoms. There are many other difficult diseases, when faced with difficult diseases, need to actively cooperate with the regular treatment, and establish confidence, maintain a good state of mind.