We all get thirsty at various points throughout the day. And there are plenty of situations where being thirsty is perfectly reasonable — after working out, while outside on a hot day or after eating a spicy or salty meal.

Feeling thirsty in the middle of the night or waking up with dry mouth, however, seems...well, less reasonable. Sure, it's been several hours since your last sip of water, but that's no different from any other night.

What does having dry mouth at night or in the morning mean?

Did you know that the average healthy adult makes at least half a liter of saliva every single day?

Yes, it's time to talk about saliva — that mucus-y mouth fluid that mostly grosses us out, despite the several important roles it plays in our everyday lives.

Your body uses saliva to:

• Rid the mouth of germs
• Prevent tooth decay
• Regulate the pH in the mouth
• Help with digestion
• Soften foods, making them easier to chew and swallow
• Limit the buildup of food debris
• Lubricate the mouth to aid in speaking
  
  

According to the American Academy of Otolaryngology-Head and Neck Surgery, when your salivary glands don't make enough saliva, it's called xerostomia, or dry mouth — and you definitely feel it.

Dry mouth is particularly noticeable if it's interrupting your sleep. But, aside from waking you up at night, dry mouth can also lead to:

• Bad breath
• Sores in the mouth
• Mouth infections
• Tooth decay, cavities and gum disease
  
  

Good oral hygiene is important for everyone, but it's particularly important if you're prone to experiencing dry mouth since it can negatively impact your teeth and gums.

If you're experiencing dry mouth at night, it's important to identify what's causing it.

Five common causes of dry mouth at night

1. Not drinking enough water throughout the day

Aside from some electrolytes, enzymes and antimicrobial molecules, saliva is primarily made up of water. So, if you're not drinking enough water, your body may not have what it needs to produce adequate amounts of saliva — resulting in dry mouth.

And, take note, chugging a bunch of water before bed isn't the solution to avoid waking up thirsty. In fact, excessive consumption of water in the evening can not only wash away some of the saliva that's currently present — potentially increasing your chances of developing dry mouth overnight — it will also likely mean waking up in the middle of the night to use the bathroom.

Maintaining proper hydration throughout the day can help ensure your body is able to produce the amount of saliva needed to limit dry mouth.

2. Medications you're taking

There are hundreds of medications associated with dry mouth, including common ones that you can find over-the-counter.

The most common causes of medication-induced dry mouth are:

• Certain drugs used to treat urinary incontinence
• Antidepressants and anxiety medications
• Blood pressure medications
• Antihistamines
• Decongestants
  
  

In addition, cancer treatments, such as chemotherapy and radiation, can also cause dry mouth. Chemotherapy-induced dry mouth is often temporary. Radiation-induced dry mouth, on the other hand, can be temporary or permanent, depending on the site and dosage of the therapy.

Talk to your doctor if you're experiencing dry mouth and think it may be caused by one or more of the medications you're taking. He or she may be able to recommend an alternative.

3. Breathing through your mouth

While you're sleeping, your meant to do most of your breathing through your nose, not your mouth. If you're mostly breathing through your mouth while you sleep, it can dry it out.

Situations that may cause you to breathe out of your mouth, rather than your nose, include:

• Your particular sleep habits
• Nasal congestion caused by allergies or a cold
• Snoring
• Sleep apnea
  
  

Experiencing dry mouth at night doesn't automatically mean you have sleep apnea, but it can be a sign of this condition — which is more common and serious than you may think. This is why it's important to talk to your doctor if you're experiencing dry mouth at night more often than not.

4. What you eat and/or drink before bedtime

Before bed, it's best to avoid the foods and drinks that typically increase thirst and/or contribute to dry mouth.

For instance, eating a particularly salty or spicy snack or meal just before bed can cause thirst that's temporary, but intense — potentially intense enough to wake you up.

Additionally, alcohol and caffeine can dehydrate your mouth, so it's best to limit both before going to bed to avoid dry mouth.

Lastly, aside from being detrimental to your overall health, smoking tobacco can reduce your salivary flow, contributing to dry mouth at night. (Related: Tips for Quitting Smoke for Good)

5. An underlying health condition

More often than not, waking up thirsty isn't so much a medical concern as it is an inconvenience. However, dry mouth can lead to poor dental health if you're not maintaining good oral hygiene. And, in some cases, dry mouth can even be a sign of an underlying health condition.

Health conditions associated with dry mouth include:

• Diabetes
• Yeast infection (thrush)
• Stroke
• Alzheimer's disease
• Sjogren's syndrome
• Nerve damage
  
  

Talk to your doctor if you're frequently experiencing dry mouth at night. He or she can ask you questions and run the tests needed to rule out a serious underlying health issue that may need attention.