Dry mouth or xerostomia

A dry mouth (or xerostomia) makes you feel like you don’t have enough saliva in your mouth.

We can all suffer from dry mouth from time to time if we:

  • Are nervous,
  • are angry,
  • Are stressed.

A mouth that is dry daily or most of the time can cause discomfort and cause:

  • Symptoms

It can also be the symptom of some diseases.

The medical term for a dry mouth is “xerostomia”.

Biology of saliva

Saliva is the product of the salivary glands.

These glands secrete a fluid into the mouth that contains:

  • Water
  • Electrolytes
  • Mucus
  • Enzymes.

Functions of saliva

Saliva has many tasks:

  1. Lubricant and binder: The mucus in the saliva amalgam (or saliva mixture) ensures that chewed food has a slimy portion and flows easily through the esophagus without damaging the mucous membrane. (Dechaume M, Goguel S, Poullain P. Human saliva: Physical properties; chemical composition; cytology; bacteriology; serological properties; role. Revue Stomatol)
  2. Enriches with water and makes dry food soluble: To make food tasty, the molecules dissolved in it must be dissolved.
  3. Oral hygiene: The oral cavity is constantly flushed through the saliva that:
  • food leftovers eliminated,
  • Keep your mouth clean all the time.

Salivation decreases considerably during sleep, causing bacteria to accumulate in the mouth.
The result is bad breath in the morning.
Saliva also contains lysozyme, an enzyme that breaks down many bacteria and prevents infection. (Dewar MR. The saliva: A short review, with special reference to dental caries. Med J Aust

Saliva helps prevent tooth decay by:

  • Inhibits bacterial growth,
  • Wash food particles from the mouth.
  1. Start of digestion of starches: Saliva amylase or ptyaline is an enzyme that begins to digest starch and converts it into maltose. (Neilson CH, Terry OP. “The adaptation of the salivary secretion to diet.” Am J Physiol)


Signs and symptoms of dry mouth (xerostomia)

Signs and symptoms of dry mouth include:

  • Halitosis
  • Cheilitis – inflammation of the lips
  • Chapped lips
  • Chapped and cracked oral mucosa (inner wall of cheeks and lips)
  • Fungal infection in the mouth, e.g. thrush (candida)
  • Altered sense of taste
  • Lipstick tends to stick to teeth
  • Common gum disease
  • Increased occurrence of dental plaque and caries
  • Swallowing and chewing problems – especially with particularly dry and crumbly foods such as crackers and cereals
  • Problems with prosthesis use – problems with the care of dentures and formation of wound sites
  • Sore throat
  • Sticky and thread-pulling saliva
  • Torn or painful corners of the mouth

Causes of dry mouth

Dry mouth can have numerous causes, including:

Side effects of certain medicinal products

Dry mouth often occurs as a side effect with many prescription and over-the-counter medications, including medicines used to treat:

  • Depression
  • anxiety (antidepressants),
  • Ache
  • allergies and colds (antihistamines and decongestants),
  • Overweight
  • Acne
  • Epilepsy
  • high blood pressure (diuretics),
  • diarrhoea (antidiarrheal medicines),
  • Nausea
  • psychotic disorders,
  • Urinary incontinence
  • asthma (certain bronchospasmolytics),
  • Parkinson’s disease.

Muscle relaxants and sedatives can also cause dry mouth.

Concomitant symptoms of certain diseases and infections

A dry mouth can occur as a side effect of certain diseases, here are some examples:

  • Sjögren’s syndrome (autoimmune disease in which the antibodies attack the exocrine glands),
  • rheumatoid arthritis,
  • systemic lupus erythematosus,
  • Alzheimer’s disease,
  • Parkinson’s disease,
  • Diabetes
  • anaemia (Johansson I, Fagernäs C. – Department of Cariology, University of Umeå, Sweden),
  • Cystic fibrosis
  • Stroke
  • Allergic reaction.

Stroke and Alzheimer’s disease can provoke the feeling of dry mouth, although the salivary glands function normally. Snoring with an open mouth can promote dry mouth at night.

Tumor and cancer therapy

Dry mouth as a side effect of certain forms of treatment. Damage to the salivary glands (glands that produce saliva) can be caused by radiation therapy to treat the head and neck region or chemotherapy for cancer treatment. In this case, the amount of saliva decreases.

Signs of aging

Aging in itself is not a risk factor for dry mouth.

But older people often take medications that cause dry mouth.

In addition, in old age there is an increased likelihood of diseases that provoke dry mouth.

During menopause, saliva production decreases because estrogen levels drop.

Nerve damage

An accident or surgical procedure can cause nerve damage in the neck and head area and cause xerostomia.


In the first months of pregnancy, dry mouth may occur, even if the woman drinks more than usual.

Cigarette or cigar smoking

Smoking or chewing tobacco can increase dry mouth.


Dry mouth in the morning

When getting up in the morning, it is very easy to have a dry and sticky mouth, because the body produces less saliva at night; in addition, the little saliva in the mouth dries out when you sleep with your mouth open.

Dry mouth when talking or running

Activities such as running or talking are done with his mouth open and therefore it is quite normal for him to become dry.

At conferences, it is recommended that a bottle of water be ready, especially on stage, because emotional situations can affect salivation.

Diagnosis of dry mouth

To diagnose dry mouth, the doctor or dentist examines the mouth and asks the patient about his medical history.

Sometimes blood tests, diagnostic imaging techniques such as MRI or scintigraphy of the salivary glands, or other examination methods to measure the amount of saliva produced (sialometry) must be performed to determine the cause.

In diabetics, blood sugar must be controlled.

Therapy for dry mouth

Artificial saliva

The doctor may prescribe an oral spray or oral gel that serves as a saliva substitute. Each dose has a temporary effect, so frequent use must be carried out.

Stimulation of salivation

In some cases of dry mouth, the salivary glands are only partially impaired and can be stimulated to increased saliva production.

Chewing sugar-free gum can help with saliva production and salivation.

Pilocarpine is a drug that can stimulate the salivary glands to produce more saliva. It may be prescribed if other measures do not have a sufficient effect.

Most often, pilocarpine has a good and quick effect in many people whose dry mouth occurs as a side effect of a drug.

If dry mouth is caused by radiotherapy, pilocarpine is not particularly effective.

Pilocarpine can cause side effects in some people, such as:

  • Sweats
  • Vertigo
  • Runny nose,
  • blurred vision,
  • Frequent urination.

However, the side effects subside over time as the body gets used to the substance.

The doctor might recommend a low dose at the beginning, which is taken until the side effects subside.

Then the amount can be gradually increased with the aim of achieving the maximum effect with minimal side effects.

Pilocarpine should not normally be taken in:

  • Asthma
  • Chronic obstructive pulmonary disease (COPD),
  • bradycardia (decreased heart rate),
  • Ileus
  • Angle-closure glaucoma.

Change in lifestyle habits and natural remedies for dry mouth

If the cause of the problem cannot be identified or resolved, the following measures can help to improve the symptoms of dry mouth and keep teeth healthy:

  • Chew sugar-free gum or suck sugar-free, hard candy, although other health problems may occur because these products contain aspartame and other sweeteners or additives.
  • Eating foods that stimulate salivation, especially indicated are citrus fruits: lemon, orange and grapefruit.
  • If there are no contraindications, a fasting cure can help cure the diseases that cause dry mouth.
  • Limit caffeine consumption. Caffeine can cause dry mouth.
  • Avoid candy and sugared or acidic foods because they increase the risk of tooth decay.
  • Do not use alcohol-containing mouthwash because alcohol can increase dryness.
  • Quit smoking and do not enjoy chewing tobacco.
  • Drink sips of water during the day or suck ice cubes to keep your mouth moist, and drink water during meals to aid in chewing and swallowing.
  • Over-the-counter saliva substitutes There are products that contain carboxymethylcellulose or hydroxyethylcellulose, such as the mouthwash Biotene.
  • Avoid over-the-counter antihistamines and decongestants as they may increase symptoms.
  • If possible, breathe through the nose and not through the mouth.
  • Increase the humidity in the room with the help of a humidifier.

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