Many elderly people often feel dry mouth, which may be aggravated in the morning, and in severe cases it is difficult to swallow even if they eat steamed bread without drinking water, and they usually feel sticky saliva. Even if you take a lot of medicines to remove fire and pay attention to drink more water, the improvement is not obvious. Dry Mouth (Dry Mouth) is a symptom caused by the reduction of saliva caused by a variety of factors, and is a physiological or pathological phenomenon. The function of the body organs of the elderly will have different degrees of degeneration, which is a kind of ageing change, manifested in the oral cavity is more obvious and early to appear, is the quantity and quality of saliva changes, dry mouth and other symptoms. Some elderly people not only feel dryness in the mouth, but also have foreign body sensation and burning sensation. When chewing dry food, it affects swallowing. Moreover, due to the decrease of saliva secretion, the scouring and cleaning effect of teeth is weakened, which increases the risk of developing root surface caries and periodontal disease of elderly teeth and has a great impact on the oral health condition. Saliva is an important part of the oral micro-ecological environment, it is a mixed fluid that includes the secretions of the three major salivary glands (parotid, submandibular and sublingual) and many minor salivary glands, microorganisms and their metabolites, food residues and even nasal secretions. More than 99% of saliva is water. A normal adult produces 1 to 1.5 L of saliva per day. The amount of saliva produced is not constant and often varies according to mood, climate change and age, and is also influenced by a variety of factors such as food, medications, and health status. The effects of diet on saliva flow rate and composition can occur through local reflexes and systemic effects. The main effect of diet on saliva composition is the alteration of plasma composition, most notably manifested by a direct relationship between plasma and saliva urea concentration. The rate of static salivary flow in adults varies considerably throughout the day. Some studies suggest that static saliva flow rates are higher in the afternoon and evening than in the early morning and morning. The lowest flow rate in the early morning may be one of the reasons why many people experience significant dry mouth upon rising in the morning. Salivary secretion varies seasonally, peaking in winter, decreasing to low levels in summer, and then gradually increasing again. The decrease in salivary flow rate in summer is most likely related to sweating and mild dehydration. Saliva flow rate is lower in women than in men, and it is more common for women to feel dry mouth in clinical practice. Salivary flow rate also decreases after menopause in healthy women with no history of medication use. Older adults usually complain of dry mouth. There have been many studies looking at the effects of aging on the salivary glands. It has been suggested that salivary flow rates tend to decrease with age, possibly due to a decrease in the active secretory component of the gland. The following six factors can cause dry mouth: 1. Salivary gland abnormalities: There are many reasons that can lead to gland destruction or atrophy, resulting in impaired salivary secretion, such as desiccation syndrome, nasopharyngeal or oral and maxillofacial malignant tumors after radiation therapy, etc.. This dry mouth symptom is significantly reduced when there is no stimulation or stimulated with acidic drugs, saliva secretion, dry oral mucosa, and language and swallowing difficulties can occur in severe cases. 2, drugs: the most common side effect of many drugs is that they can reduce salivary secretion and cause dry mouth. Especially for elderly women, when they take anti-hypertensive or histamine drugs, it can cause reduced salivary secretion and obvious dry mouth. Some scholars have compiled a large number of drug books and summarized fourteen categories of drugs that can cause dry mouth. The most common ones are anti-acetylcholine drugs (atropine and belladonna agents), anti-hypertensives and psychiatric drugs. The symptoms of dry mouth can be relieved soon after stopping the medication. 3, systemic condition: the metabolism of salivary glands depends on the systemic metabolic condition. Such as diabetes, uremia, dehydration, hyperthermia, severe vomiting, diarrhea, acute renal failure polyuric phase, excessive sweating in a hot environment, etc., all have an impact on the role. Increased water demand and insufficient water intake of the body, so that saliva production is reduced and dry mouth. 4, psycho-neurological factors: due to the influence of psychological factors, central salivary secretion abnormalities can occur. Some patients with neurasthenia often have dry mouth symptoms, but most of them are temporary. Check the patient’s oral mucosa without obvious dryness, although salivary secretion decreases when there is no stimulation, but salivary secretion does not decrease after stimulation with acidic drugs. Middle-aged and elderly women are also often accompanied by dry mouth, oral mucosa pain, burning sensation, which may be due to menopause, but also may be suffering from a disease called burning mouth syndrome. 5, oral local factors: due to nasal polyps, nasal septum curvature and other reasons caused by poor nasal ventilation, open mouth breathing people after a night of mouth breathing, even if the amount of saliva secretion is normal, the same will be obvious dry mouth symptoms. Missing teeth, dental caries, periodontal disease, unsuitable denture and other factors cause the chewing function to decline, the stimulation of salivary glands and chewing muscles is reduced, which can also cause saliva secretion to decrease. 6, oral candida infection: full total denture use too long, the intermaxillary distance is too low; long-term wear movable dentures, do not pay attention to oral hygiene and denture cleaning of the elderly are particularly prone to infection Candida albicans, due to mycelia proliferation and lead to dry mouth. Similarly, elderly people with anemia are also prone to oral candida infection. Therefore, if elderly people have symptoms of dry mouth, they should generally consider whether they have a history of long-term medication use, whether they have bad habits such as mouth breathing, and whether they have fungal infections due to long-term use of removable denture. If these factors are ruled out and the symptoms of dry mouth are not relieved, you should go to the hospital to see a doctor to find out the cause and do targeted treatment.