Dry syndrome is a chronic inflammatory autoimmune disease that mainly involves exocrine glands, also known as autoimmune exocrine gland epithelial cellulitis or autoimmune exocrinopathy. In addition to dry mouth and eyes due to decreased function of salivary glands and lacrimal glands, other exocrine glands and other organs outside the glands are also involved, resulting in symptoms of multisystem damage. The disease is characterized by a variety of autoantibodies and hyperimmunoglobulinemia in the serum. The disease is divided into two categories: primary and secondary. Primary dry syndrome is a global disease, the prevalence of which is 0.3%-0.7% in our population, and 3%-4% in the elderly population. The disease is more common in women, and the ratio of men to women is 1:9-20. The age of onset is mostly 40-50 years old. It is also seen in children. Not necessarily dry mouth and dry eyes are dry syndrome. Many common conditions can cause dry mouth and dry eyes: 1. Viruses: mumps, EBV, HIV, HTLV-1. 2. Graft-versus-host disease. 3.Nodular disease. 4.Lymphoma. 5.Radioiodine therapy. 6.Fibromyalgia-like syndrome: chronic fatigue syndrome. 7.Aging. 8.Abnormal lipoproteinemia. 9.Hemochromatosis. 10.Bulimia. It can be seen that not all patients with dry mouth and dry eyes are regarded as dry syndrome, and it is still necessary to exclude the above diseases and meet the diagnostic criteria of dry syndrome before diagnosis.