Elderly people often feel dry mouth and dry eyes, and it is more obvious at night, so they need to drink water to fall asleep again. Most people think that this is not a disease, probably because the weather is too dry or because of old age. This is indeed a cause, as well as the installation of dentures, open-mouth breathing at night while sleeping or taking certain medications can also cause dry mouth. However, if dry mouth and eyes are more obvious, or if you have swollen parotid glands, swollen and painful joints, or flaky teeth, you need to be alert to whether you have dry syndrome. Dry syndrome is a kind of systemic chronic rheumatic disease that mainly affects the lacrimal and salivary glands. The cause is still unclear, and it is most common in women over 50 years old. Mouth: About 70% to 80% of patients have dry mouth symptoms, severe cases need to drink water frequently when speaking, and need to eat solid food accompanied by water or liquid food sent down, sometimes need to get up at night to drink water. 50% of patients can develop uncontrollable dental caries, teeth gradually become black, followed by flaky loss. The tongue is dry and cracked, and the oral cavity is often infected with mycobacteria. 50% of patients may have mumps, which is characterized by alternating painful swelling of the parotid glands, which may subside on its own in about 10 days, and sometimes may remain enlarged. Dry eyes: Patients may also have dry eyes, foreign body sensation, and few tears due to reduced mucin secretion from the lacrimal glands, and in severe cases, painful crying without tears. Dryness of other parts: Other superficial parts such as skin, nasal mucosa, digestive tract mucosa and vaginal mucosa can be dry due to the reduction of glandular secretion. In addition to dryness of the mouth and eyes, patients can also develop systemic symptoms such as malaise and fever, and about 2/3 of patients can develop systemic damage. Skin, muscle and joint involvement: skin manifests as vasculitis, such as allergic purpura-like rash, mostly in the lower extremities, rice-grain-sized red papules with clear borders that do not fade when pressed, appear in batches, and last for about 10 days to fade on their own. Patients may have myalgia and non-deforming arthritis or arthralgia. Respiratory involvement: Most patients have no respiratory symptoms. Mild involvement may result in a dry cough, and severe involvement may result in shortness of breath, and the lungs may show chronic bronchitis, interstitial pneumonia, interstitial fibrosis and abnormal pulmonary diffusion function. Digestive system involvement: Gastrointestinal exocrine gland lesions present with atrophic gastritis, decreased gastric acid, and dyspepsia. About 20% of patients have liver damage, which may be accompanied by primary biliary cirrhosis or autoimmune hepatitis. Renal involvement: About 30% to 50% of patients have renal damage, which may present with subclinical forms of tubular acidosis, renal tubular acidosis and glomerulonephritis. Clinical manifestations may include hypokalemic muscle paralysis and proteinuria. Hematologic involvement: Decline in white blood cells, hemoglobin and platelets may occur. Patients with significant platelet decline may have bleeding tendency. If symptoms appear in the above, please go to the Rheumatology and Immunology Department in time. Further diagnosis of dry syndrome requires relevant serum immunological examination, oral or ophthalmic examination. Once the diagnosis is confirmed, treatment should be standardized. The course of the disease is slow and the prognosis is good. If systemic damage occurs, the prognosis is poor. Therefore, it is very important to seek medical treatment as early as possible to control the disease in the cradle.