13 Possible Causes Of Dry Mouth

causes of dry mouth

A dry, parched mouth, bad breath, blisters, and trouble swallowing – not a pleasant picture, is it? But around 10% of the general population suffer from dry mouth, a condition that can affect your oral health, well-being, and even your ability to talk and eat properly.1

People with dry mouth, medically known as xerostomia, don’t have sufficient saliva in their mouth. And we all know the humble saliva plays a crucial role in oral health. It has antibacterial, antiviral, and antifungal properties and helps to neutralize teeth-destroying acid produced by plaque. Saliva, thanks to its calcium and phosphorus content, also helps rebuild teeth enamel. If you have dry mouth, you can expect mouth infections, tooth decay, gum disease, dry lips, and soreness or a burning sensation in your mouth. This condition can also affect your ability to speak, swallow, and taste properly. Which is why it’s important to understand what causes it.


Causes Of Dry Mouth

Stress and anxiety can cause our mouths to dry up. But this temporary reaction is quite normal and should settle down once the moment has passed. However, some medical issues can also lead to persistent or recurring dry mouth.2 3 4 5 6 7 8 9 10 11

1. Dehydration

If you are dehydrated and don’t have sufficient fluids in your body to produce enough saliva, you could experience dry mouth. Dehydration can be caused by not taking in enough fluids. Some medical conditions like kidney disease, diabetes, diarrhea, and vomiting can also lead to dehydration.


Thirst and passing urine that’s darker in color are early signs that you’re dehydrated. You may also pass less urine and get headaches and muscle cramps when you feel dehydrated. Other symptoms include feeling dizzy, nauseous, and tiredness.

If you experience loss of consciousness, feel confused, haven’t passed urine for eight hours, and have a rapid or weak pulse, you could be severely dehydrated. This should be treated as a medical emergency.


2. Mouth Breathing

Breathing through your mouth instead of your nose can leave you with a dry mouth. People who sleep with their mouth open may often wake up with a rough tongue or dry lips. Mouth breathing generally develops when your nasal airways are obstructed. Many conditions like enlarged tonsils, nasal polyps, enlarged adenoids, allergic rhinitis, a deviated nasal septum etc. can cause nasal obstructions.

Various other medical conditions can also cause dry mouth.


3. Diabetes

Diabetes, a disease in which blood sugar levels are abnormally high, can also result in dry mouth. Alongside dry mouth, if you experience increased thirst, fatigue, itching around your genitals, blurred vision, or need to pass urine more frequently, it’s a good idea to get tested for diabetes.


People with human immunodeficiency virus (HIV) can experience oral health issues, including dry mouth. This virus damages your immune system by destroying infection-fighting cells, thus leaving you vulnerable to a host of infections as well as certain cancers. HIV can be spread by having unprotected sex with someone who is infected. It can also spread by sharing needles or coming into contact with infected blood. You can also pass it to your baby when you’re pregnant or during delivery.


Infection by HIV may initially cause a flu-like illness, rash, and swollen glands which resolve within 2 to 4 weeks. You may then be without any symptoms for a long period of time. However, after a while, you may experience more severe symptoms like weight loss, fever, diarrhea, swelling of glands in your neck, armpits, or groin, sores, rashes etc.

5. Salivary Gland Infection

[pullquote]It’s important to pay extra attention to your oral hygiene if you have a dry mouth to lower the risk of dental problems. Also, schedule regular appointments with your dentist so that any problems can be identified and fixed early.[/pullquote]


If your salivary glands become infected with bacteria or virus, it can cause inflammation and reduce the production of saliva. This can cause dry mouth. An example of an infection that affects your salivary glands would be mumps. Bacterial infection due to poor hygiene, smoking, or chronic illnesses can also be responsible. Look out for other symptoms like a foul taste in the mouth, difficulty opening mouth fully, fever, and mouth or facial pain.

6. Salivary Duct Obstruction

An obstruction of your salivary glands can cause dry mouth. For instance, if minerals in your saliva form stones that block your salivary ducts, it can restrict the flow of saliva. This will cause the affected salivary gland to swell up. Apart from swelling and dryness, you will also experience pain along the gland. Both the pain and swelling may get worse when you eat.


7. Sjögren’s Syndrome

[pullquote]If you have Alzheimer’s disease or stroke your ability to experience the feeling of wetness in your mouth may be diminished. This can make you feel like your mouth is dry.12[/pullquote]

Sjögren’s syndrome, a condition where your immune system mistakenly damages salivary and sweat glands, can result in dry mouth. Other symptoms include dry eyes, dry skin, joint or muscle pain, dryness in the vagina, swelling of the salivary glands which are present between your ears and jaw, and rashes.

8. Medication

Around 600 medicines, including some which are used to treat depression, allergies, high blood pressure etc. are known to lead to dry mouth. Illegal drugs like cocaine can also cause this condition. Do check in with your doctor to find out if any medication that you are on is responsible for the dryness in your mouth.

9. Radiotherapy

Radiation therapy to your face, head, or neck can cause dry mouth. It can take over 6 months after your treatment ends for your salivary glands to begin producing saliva again. Although you can expect to see some improvement in this condition in the first year after treatment, some people continue to suffer from some level of chronic dry mouth after radiation therapy. This is particularly true if the treatment focused on the salivary glands.

10. Chemotherapy

Chemotherapy can make your saliva thicker, resulting in dry mouth. However, this is temporary and your dry mouth should clear up around 2 to 8 weeks after you stop treatment.

11. Nerve Damage

The functioning of your salivary glands is regulated by facial nerves. Any injuries to your neck or head that damage these nerves can cause a decrease in the production of saliva.

12. Hormonal Changes

Hormones like estrogen seem to have an influence on the composition and flow of saliva. Therefore, women are likely to suffer from dry mouth during pregnancy and menopause due to the hormonal changes associated with these.

13. Lifestyle Factors

Drinking alcohol, smoking or chewing tobacco, and having caffeine can all contribute to having a dry mouth.

What Can You Do About It?

Treating the underlying cause of dry mouth can improve your condition. Your doctor may recommend the use of artificial saliva in some cases. Meanwhile, here are some measures that you can take that can be helpful.

  • Take sips of water regularly as increasing your fluid intake can help keep your mouth moist.
  • Chew on sugar-free gum as this can stimulate your salivary glands and increase saliva.
  • Avoid alcohol, caffeine, and smoking as these can dry your mouth out.13