What could cause more saliva on one side of the mouth?

Reviewed by Yoshinori Abe, MD

Internal Medicine

Uneven saliva on one side of the mouth usually happens when a salivary gland on that side is overactive, blocked, or irritated, or when the nerves and muscles controlling saliva flow aren't working evenly. Common causes include salivary stones, gland infections, dental issues, nerve irritation, or one-sided facial muscle weakness. In some cases, it may point to an underlying neurological or oral health condition that needs evaluation.

Because the causes range from minor to more serious, it's worth clarifying your specific symptoms before deciding what to do next. A free, instant, online symptom check can help you understand possible explanations based on your unique situation and guide you toward the right next steps — whether that's monitoring at home, seeing a dentist, or consulting a doctor. It takes only a few minutes and could save you time, worry, and unnecessary guesswork.

Reviewed for medical accuracy: 07/15/2026

Important Next Steps

Learn what causes one-sided excess saliva Discover if your saliva changes need care See if it could be a nerve issue Find OTC options for drooling relief Find a doctor for mouth symptoms Understand home remedies for excess saliva Check likely causes of one-sided drooling

Not seeing your question? No worries.

Submit your own Question

Explanation

There are a few reasons you might notice extra saliva on one side of your mouth. One possibility is that the salivary glands, like the parotid or submandibular glands, are not working the same on both sides. The gland on one side might be more active or inflamed, which can lead to producing more saliva.

Another reason could be that the nerves and muscles, which help control swallowing and keep saliva in, might not work as well on one side. When these parts do not work in harmony, the saliva can pool on one side. Some medications and certain health conditions can affect saliva production in an uneven way too. Each part of your face plays a role in directing saliva normally, so if there is a small imbalance, you might see more liquid on one side.

If this extra saliva causes discomfort or you are worried, you can use Ubie's free symptom checker to help understand your symptoms better and determine if you should seek medical care.

(References)

Lakraj AA, Moghimi N, Jabbari B. Sialorrhea: anatomy, pathophysiology and treatment with emphasis on the role of botulinum toxins. Toxins (Basel). 2013 May 21;5(5):1010-31. doi: 10.3390/toxins5051010. PMID: 23698357; PMCID: PMC3709276.
Miranda-Rius J, Brunet-Llobet L, Lahor-Soler E, Farré M. Salivary Secretory Disorders, Inducing Drugs, and Clinical Management. Int J Med Sci. 2015 Sep 22;12(10):811-24. doi: 10.7150/ijms.12912. PMID: 26516310; PMCID: PMC4615242.
Iorgulescu G. Saliva between normal and pathological. Important factors in determining systemic and oral health. J Med Life. 2009 Jul-Sep;2(3):303-7. PMID: 20112475; PMCID: PMC5052503.

Thinking about asking ChatGPT?Ask me instead

Tell your friends about us.

We would love to help them too.

For First Time Users

What is Ubie’s Doctor’s Note?

We provide a database of explanations from real doctors on a range of medical topics. Get started by exploring our library of questions and topics you want to learn more about.

Was this page helpful?

Purpose and positioning of servicesUbie Doctor's Note is a service for informational purposes. The provision of information by physicians, medical professionals, etc. is not a medical treatment. If medical treatment is required, please consult your doctor or medical institution. We strive to provide reliable and accurate information, but we do not guarantee the completeness of the content. If you find any errors in the information, please contact us.