Drooling: Symptoms, Causes and Treatment

Drooling—also known as sialorrhea—is a common phenomenon that can affect people of all ages, but is particularly prevalent in children with neurological conditions and adults with certain diseases. While often seen as a simple nuisance, drooling can have far-reaching impacts on physical health, social interactions, and quality of life. In this comprehensive article, we will explore the main symptoms, underlying causes, and current treatment strategies for drooling, drawing on the latest research and clinical evidence.

Symptoms of Drooling

Drooling is more than just the visible loss of saliva from the mouth—it can manifest in a variety of ways, affecting daily life, physical comfort, and even long-term health. Understanding the range of symptoms is crucial for effective diagnosis and management.

Symptom	Description	Impact	Source(s)
Saliva Overflow	Unintentional loss of saliva from mouth	Discomfort, social stigma	1 4 5
Coughing/Choking	Reaction to saliva pooling or aspiration	Distress, risk of aspiration	1 2
Congested Breathing	Difficulty due to saliva in airways	Sleep disturbances, distress	1
Silent Aspiration	Saliva entering lungs without symptoms	Chest infections, lung damage	1
Oral Soreness	Irritation around mouth/chin	Skin breakdown, infection	4
Dental Issues	Increased risk of dental caries	Oral health complications	1
Social/Emotional	Embarrassment, isolation	Reduced quality of life	5

Table 1: Key Symptoms of Drooling

Common Physical Symptoms

The most obvious sign of drooling is the unintentional leakage of saliva from the mouth, which can dampen clothes, skin, and even objects nearby. In more severe cases, especially with neurological involvement, drooling can result in coughing or choking as saliva pools at the back of the throat or is aspirated into the lungs. For many, this leads to congestion, noisy breathing, and recurrent respiratory infections 1 2 4.

Hidden Dangers: Aspiration and Respiratory Risks

Perhaps more concerning is "silent aspiration"—when saliva enters the lungs without triggering a noticeable cough or distress. This is particularly common in children with neurological impairment or adults with conditions like Parkinson’s disease, and it can lead to repeated chest infections and even long-term lung damage 1.

Oral and Skin Complications

Persistent moisture from drooling can cause skin breakdown around the mouth and chin, sometimes resulting in rashes or infections. Additionally, there is evidence that some treatments for drooling, particularly surgical interventions, may increase the risk of dental caries, especially in areas not typically prone to decay 1.

Psychosocial Impact

Beyond the physical, drooling can have a profound impact on self-esteem, social participation, and overall well-being. Many people with drooling experience embarrassment, stigma, and social isolation, affecting both patients and their families or caregivers 5.

Causes of Drooling

Drooling does not have a single cause—instead, it is usually the result of a combination of physiological, neurological, and sometimes anatomical factors. Understanding these underlying mechanisms is essential for both accurate diagnosis and effective treatment.

Cause	Mechanism/Trigger	Affected Group(s)	Source(s)
Swallowing Dysfunction	Inefficient, infrequent, or uncoordinated swallowing	Children with CP, PD patients	2 3 4 5 6
Oral Motor Deficits	Weakness or incoordination of mouth muscles	CP, other neurological conditions	2 4 8
Hypersalivation	Excess saliva production (rare)	Medication side effects, some diseases	2 4
Hypomimia	Reduced facial movement/mouth opening	Parkinson’s disease	3
Oropharyngeal Bradykinesia	Slow oral and pharyngeal muscle movement	Parkinson’s disease	6
Anatomical Abnormalities	Structure impeding normal swallowing or closure	Various	4
Posture and Nose Breathing	Poor posture or inability to breathe through nose	Parkinson’s, disabled	3 4
Age and Development	Normal in infants/toddlers	Young children	2 8

Table 2: Primary Causes of Drooling

Swallowing Dysfunction

The most common underlying cause of drooling is a dysfunction in the swallowing mechanism. This can manifest as infrequent or inefficient swallowing, which fails to clear saliva from the mouth regularly. Children with cerebral palsy (CP) or adults with Parkinson’s disease (PD) frequently experience this type of dysfunction due to impaired neuromuscular coordination 2 3 4 5 6. In CP, studies show that drooling is closely linked to both inefficient and infrequent swallowing 2.

Oral Motor Impairments

Deficits in voluntary oral motor activity—such as poor lip closure, weak tongue muscles, or inability to maintain an effective oral seal—can contribute significantly to drooling. These issues are particularly pronounced in children with neurological impairments, but may also occur in other conditions affecting muscle control 2 4 8.

Hypersalivation: Less Common, Still Relevant

While many assume that drooling is due to excessive saliva production, true hypersalivation is actually rare. It may be seen as a side effect of certain medications or in specific medical conditions, but for most, the problem lies with impaired clearance rather than overproduction 2 4.

Parkinson’s Disease Mechanisms

In Parkinson’s disease, drooling is multifactorial. Research highlights the role of hypomimia (reduced facial expressiveness and mouth opening), oropharyngeal bradykinesia (slowed muscle movement in mouth and throat), and the inability to maintain proper posture 3 5 6. Patients may also subconsciously increase their swallowing frequency to compensate for less effective swallowing 3.

Anatomical and Developmental Factors

Occasionally, anatomical abnormalities—such as enlarged tonsils, structural oral defects, or nasal blockages—can impede normal swallowing or mouth closure, leading to drooling 4. In infants and toddlers, drooling is often a normal part of development as oral motor skills mature 2 8.

Additional Influences: Age, Mobility, and Severity

Other factors such as age, mobility, and the degree of oral motor involvement can influence the likelihood and severity of drooling. Some studies suggest that spontaneous improvement is possible in certain children as they age and develop better oral control 8.

Treatment of Drooling

Treating drooling requires a tailored approach that considers the underlying cause, severity, patient age, and overall health status. There is no one-size-fits-all solution, but a variety of therapies—from behavioral interventions to surgery—are available.

Treatment	Approach/Method	Typical Use/Indication	Source(s)
Behavioral Therapy	Oral motor exercises, biofeedback	Mild to moderate cases, children	4 8
Oral Stimulation	Feeding/oral stimulation programs	Some children, limited effect	8
Medication	Anticholinergics (e.g., scopolamine, glycopyrrolate), dopaminergic agents	Moderate to severe cases, neurological patients	5 9 10
Minimally Invasive	Botulinum toxin injections in salivary glands	Refractory or severe cases	1 5 7
Surgery	Submandibular gland excision, parotid duct rerouting	Persistent, severe drooling	1 11
Supportive Care	Skin care, dental hygiene, bibs	All patients, symptom management	1 4

Table 3: Main Treatment Options for Drooling

Behavioral and Oral Motor Interventions

For mild to moderate drooling—especially in children—behavioral therapies such as oral motor exercises, biofeedback, and orofacial regulation therapy can be useful. These approaches aim to improve muscle strength and coordination, increase swallowing frequency, and teach better saliva control 4 8. However, studies suggest that oral stimulation and feeding programs may be less effective compared to other interventions 8.

Pharmacological Treatments

Medications to reduce saliva production or improve oral muscle function are widely used, particularly in those with neurological conditions:

• Anticholinergic Drugs: Agents like glycopyrrolate, benztropine, and scopolamine can decrease saliva production. Evidence suggests some efficacy, but side effects—such as dry mouth, blurred vision, constipation, or confusion—can limit their use, especially in children and the elderly 9 10. Scopolamine patches, for example, have shown success but require careful patient selection due to potential adverse effects 10.
• Dopaminergic Agents: Used in Parkinson’s disease to improve swallowing and oral muscle function, but are often not fully effective for drooling 5.

Botulinum Toxin Injections

Minimally invasive therapy using botulinum toxin (Botox) injected into the major salivary glands (parotid and submandibular) has proven highly effective in reducing drooling, with a good safety profile and minimal side effects 1 5 7. This approach is often used in patients who have not responded to conservative treatments or who are not candidates for surgery.

Surgical Interventions

For persistent, severe drooling that does not respond to other treatments, surgery may be recommended. Common procedures include:

• Submandibular Gland Excision (SMGE): Removal of the submandibular glands, which produce a significant portion of saliva, has demonstrated good long-term results 1 11.
• Parotid Duct Rerouting: Redirects saliva flow to reduce anterior drooling, often performed alongside gland excision 11.
• Other Procedures: Bilateral ligation of salivary ducts and other glandular surgeries have also been described 1.

While generally effective, surgical treatments carry risks such as increased dental caries and require careful patient selection and follow-up 1 11.

Supportive and Preventive Care

Regardless of treatment pathway, supportive measures are crucial. These include maintaining good skin care to prevent breakdown, using bibs or absorbent clothing, and ensuring regular dental hygiene to minimize oral complications 1 4.

Predicting Outcomes and Individualizing Care

Research indicates that factors such as the degree of oral motor involvement, patient mobility, and age can predict the likelihood of therapeutic success 8. Spontaneous improvement is possible in some individuals, particularly children, highlighting the importance of individualized assessment and treatment planning.

Conclusion

Drooling is a complex symptom with diverse causes and significant impacts on health and quality of life. Effective management requires a multidisciplinary, patient-centered approach.

Key Takeaways:

• Symptoms: Go beyond visible saliva; can include respiratory complications, oral and skin issues, and psychosocial distress 1 4 5.
• Causes: Most often due to swallowing dysfunction or oral motor impairments, not just hypersalivation; neurological conditions like CP and PD are common underlying factors 2 3 4 5 6.
• Treatment: Ranges from behavioral therapy and medications to minimally invasive botulinum toxin injections and surgery. Treatment choice depends on severity, cause, age, and patient preference 1 4 5 7 8 9 10 11.

By understanding the full spectrum of symptoms, causes, and treatments, patients and caregivers can work with healthcare providers to find the most effective, individualized strategies for managing drooling and improving quality of life.