Excessive saliva, which is referred to by doctors as sialorrhea, can be annoying and cause problems with eating, talking and breathing and can occur in people of any age. When excessive saliva flows out of the mouth, the condition is referred to as drooling, although excessive saliva may be contained within the mouth as well.
According to the National Library of Medicine, certain illnesses can be a cause of short-term production of excessive saliva. Tonsillitis is a common illness in children and teenagers, and may cause excessive salivation that stops after removal of the tonsils. An abscess in or around the tonsils or pharynx may also cause excessive saliva.
Respiratory infections as well as infections of certain glands can be a cause of excessive saliva, according to the National Library of Medicine. Children with a cold, influenza or nasal allergies may have excessive saliva and drool. Other infections that can cause excessive saliva include mononucleosis and strep throat.
Certain types of medications as well as hormones can cause the body to produce excessive saliva. Medications that are used for treating schizophrenia, such as clozapine, as well as some asthma medicines, including isoproterenol, can cause excessive saliva. High levels of hormones during pregnancy may be a cause of excessive saliva in women.
According to the Mayo Clinic, certain types of neurological disorders may cause the body to produce excessive saliva. Parkinson's disease and cerebral palsy may cause excessive saliva as a result of progressive nerve damage. The nerves of the salivary glands can also become damaged and cause the glands to make too much saliva.
Swallowing certain types of poisons may cause excessive salivation. According to the National Library of Medicine, pesticides can cause excessive saliva when they are swallowed. Venom from snake bites or insect stings is another type of poisoning that can cause the malady.
According to the National Library of Medicine, teething is a common cause of excessive saliva in babies and toddlers. Babies who are teething may try to put their fingers or objects into their mouths, and the saliva may flow out of the mouth and onto the hands or other objects. Excessive salivation may result in a rash on the chin or cheeks in babies who are teething, but is not a cause for medical concern.