What are the causes of dry mouth?

What is dry mouth? Also known as xerostomia, dry mouth is a condition that involves not having enough saliva to keep your mouth properly moist.¹ It’s a common condition that can affect people of all ages, though it’s more common in older adults or people taking certain medications.²

You may find yourself asking, ‘why is my mouth so dry?’, especially when it happens at night or lingers for days. While often manageable, excessive dry mouth can impact people’s daily lives, make eating and speaking uncomfortable, and can even affect their overall oral health.

In this guide, we’ll explore the most common causes of dry mouth, how it can affect your teeth and gums, and what to do for a dry mouth when it becomes a bigger problem.

What is dry mouth?

 

Dry mouth occurs when your body isn’t producing enough saliva, the clear fluid that keeps your mouth moist, helps you chew and swallow food, and protects your teeth. Symptoms of dry mouth can be temporary, but for some people, it can be a long-term issue.

 

Some of the common signs of dry mouth you may be experiencing include:^1,2

 

• Constant dry or sticky feeling in the mouth
• Cracked lips or a dry, sore tongue
• Bad breath 
• Difficulty speaking, chewing, or swallowing
• A burning or itchy sensation in the mouth
• Increased thirst
• Tooth decay or gum issues

 

If you’ve been wondering ‘what helps dry mouth?’ or ‘how to stop dry mouth from getting worse?’, identifying the cause is a key first step that you shouldn’t skip.

Common causes of dry mouth

 

There are many possible causes of dry mouth. Below are some of the most frequent triggers:

1. Medications

Many commonly prescribed and over-the-counter medications can cause dry mouth as a side effect, such as some antidepressants, antihistamines, and medications for high blood pressure.²

If you are currently taking any medication, check the leaflet that comes with it to see if dry mouth is listed as a symptom. It’s also recommended to check with your medical professional and doctor if you’re unsure.

 

2. Dehydration

One of the most straightforward answers to ‘why is my mouth so dry?’ is simply not drinking enough water.³ Heat, exercise, illness, or alcohol intake can all contribute to fluid loss, which could result in a drier-feeling mouth.

 

3. Mouth breathing

Breathing through your mouth, especially when sleeping, can lead to a dry mouth at night.³ Snoring, allergies, or a blocked nose are common culprits.

4. Anxiety

Feeling nervous or anxious can also trigger dry mouth, as it can affect saliva production.³

 

5. Medical conditions

Some chronic illnesses or health issues are linked with excessive dry mouth, such as Sjögren’s disease and diabetes.¹

6. Cancer treatments

Radiation therapy to the head and neck or chemotherapy can damage salivary glands and reduce saliva production, which can lead to excessive dry mouth.¹

 

7. Nerve damage

Injury or surgery that affects nerves in the head or neck can interfere with normal saliva flow and lead to signs of dry mouth.¹

8. Tobacco and alcohol use

Smoking, vaping, or drinking alcohol can dry out your mouth and contribute to irritation.²

What causes dry mouth at night?

 

Curious about the causes of dry mouth at night? Dry mouth at night is a particularly common complaint. It can disrupt sleep and make your mouth feel parched in the morning. Common reasons include:⁴

 

• Sleeping with your mouth open
• Snoring or sleep apnoea
• Not drinking enough water during the day
• Side effects of nighttime medications
• Alcohol consumption in the evening

 

If you wake up often asking, ‘why is my mouth so dry during the night?’, it may be time to review your bedtime routine or speak to a healthcare professional.

What is dry mouth, and how does it affect oral health?

 

Saliva plays a vital role in protecting your mouth. Without enough of it, your risk of oral health problems increases. Here are some of the potential effects of dry mouth on oral health:

 

• Tooth decay: Saliva helps wash away food and bacteria. Without it, cavities can develop faster.²
• Gum disease: A dry mouth can increase plaque buildup and lead to gum inflammation.²
• Mouth infections: People with excessive dry mouth are more prone to conditions like thrush.³
• Bad breath: A lack of saliva allows odour-causing bacteria to thrive.¹

 

That’s why knowing how to stop dry mouth and taking action early can help protect your overall oral health.

 

Alongside managing saliva levels, using the right oral care tools can make a difference. For example, the Philips Sonicare DiamondClean Prestige 9900, which provides personalised care for your teeth and gums with its advanced SenseIQ Technology, sensing pressure, motion, and coverage up to 100 times per second. If you brush too hard, it automatically adjusts the intensity to protect sensitive teeth and gums, helping you maintain a healthy smile even when dry mouth makes oral care more challenging.

What helps dry mouth? Tips and remedies

 

If you're dealing with a dry mouth, don't fret! There are plenty of simple things you can do to try to ease symptoms at home. Here’s what to do for dry mouth:^1,3

 

• Stay hydrated
• Sip water throughout the day
• Avoid caffeine and alcohol, which are dehydrating
• Chew sugar-free gum or suck on lozenges – this can stimulate saliva production
• Look for xylitol-based products for added oral health benefits
• Avoid dry foods that can be difficult to swallow and irritate the tongue  or mouth
• Use a humidifier at night, which adds moisture to the air and can reduce dry mouth at night
• Switch to alcohol-free mouthwash, as alcohol-based rinses can worsen dryness
• Avoid tobacco, as these dry out the mouth and irritate tissues
• Try to breathe through your nose

 

If home remedies for dry mouth aren’t helping and your symptoms won’t go away, speak to your GP or dentist. They may be able to figure out the cause of your symptoms and prescribe treatment for it.

 

Remember, knowing how to get rid of dry mouth often starts with understanding what’s causing it. With the right support, most people can manage symptoms themselves and avoid complications.

 

Dry mouth might seem like a minor annoyance, but when left untreated, it can lead to discomfort and more serious dental issues. If you’re looking for tips on how to stop dry mouth, simple lifestyle changes and professional advice can go a long way.