Dry Mouth Causes

Dry mouth, or xerostomia, can be extremely uncomfortable. Although dry mouth is a symptom itself, it comes with a range of other symptoms, from difficulty speaking and eating to increased risk of oral infections and tooth decay. There are several different treatment options, but figuring out what will work best for you often entails diagnosing the underlying cause. Here’s a look at what causes dry mouth. 

Medications

Ultimately, dry mouth occurs because something interferes with the production of saliva from the salivary glands. In many instances, this is the side effect of a medication. Essentially, the medications that have this effect are designed to stop or slow down some of the functions your body performs automatically -- including the water production that creates saliva. Some of the more obvious of these medications include antihistamines and decongestants, among the purposes of which is reducing mucus production. Other types of medications include: 

Medications designed to help manage high blood pressure, including alpha blockers, beta blockers, and ACE inhibitors. 
Antipsychotics and medication for anxiety, depression, and other mental or behavioral disorders. 
Bronchodilators, muscle relaxants, medication for nerve pain, and other pain medications.  

Drugs used to control an overactive bladder may also cause xerostomia; these medications are aimed at controlling the muscle spasms that make your bladder overreact. In this instance, dry mouth can be extremely frustrating, as it leads to drinking more liquid than normal in an attempt to alleviate the dry mouth, thus creating a vicious circle. Gastrointestinal medications (antidiarrheals, proton pump inhibitors, and antiulcer medications, specifically) work similarly, and so also can cause dry mouth. 

Similarly, antibiotics can cause dry mouth while simultaneously increasing the risk of fungal infections, like thrush -- which dry mouth already increases the chances of. Diuretics are designed to pull fluid from your body and can cause dry mouth; they are often used to treat issues like heart failure to help alleviate excess fluid buildup. 

Treatments and Traumas

Some cancer treatments can also cause dry mouth. Chemotherapy changes both the amount of saliva produced and certain other aspects of spit. Radiation therapy specific to the head or neck may also impact the production of saliva -- although in some cases this is not chronic -- by damaging surrounding nerves. 

Similarly, trauma to the head and neck, whether through injury or surgical procedures, may interfere with the salivary glands function. Dry mouth is also a symptom of a variety of underlying disorders, particularly those that affect the autoimmune system. HIV/AIDS and Sjogren's syndrome in particular are known for this. 

While stroke and Alzheimer's disease may appear to impact salivary production, the salivary glands are generally fine, despite the appearance of a dry mouth. Furthermore, although some people think dry mouth is a natural part of aging, this isn’t so. The truth of the matter is that older people are more likely to take medications or have medical issues that cause dry mouth. Some bad habits, such as tobacco use or taking illicit drugs, particularly methamphetamine, may also cause dry mouth.