Hypersalivation describes the presence of an excess of saliva in the mouth, either because it is being overproduced by the salivary glands, or it is not being properly cleared from the mouth. Where the patient either cannot keep their mouth closed, or is unable to swallow, it can lead to drooling.
Several conditions can cause hypersalivation, from the very serious like rabies, to the mundane such as infections in the mouth. It can also be a side effect of several medications, such as ketamine and risperidone, or toxins such as mercury and organophosphates. As such, it is not very specific, but requires further investigation and is helpful in a differential diagnosis.
In palliative care, patients who hypersalivate can be given medication that can cause a dry mouth to reduce their saliva production.