Normal spitting up doesn't interfere with a baby's well-being. As long as your baby seems comfortable and is eating well and gaining weight, there's little cause for concern. If your baby is gaining weight, then he or she isn't being harmed by the calories lost through spitting up.
http://www.mayoclinic.org/healthy-lifestyle/infant-and-toddler-health/in-depth/healthy-baby/art-20044329
If you do not make enough saliva, your mouth can become quite dry. This condition is called dry mouth (xerostomia). Dry mouth causes the gums, tongue, and other tissues in the mouth to become swollen and uncomfortable. Germs thrive in this type of setting. A germy, dry mouth leads to bad breath.
http://www.webmd.com/oral-health/what-is-saliva
Saliva is a clear liquid made by several glands in your mouth area. Saliva is an important part of a healthy body. It is mostly made of water. But saliva also contains important substances that your body needs to digest food and keep your teeth strong.
http://www.webmd.com/oral-health/what-is-saliva
Social attitudes towards spitting have changed greatly in Western Europe since the Middle Ages. Then, frequent spitting was part of everyday life, and at all levels of society it was thought ill-mannered to suck back saliva to avoid spitting.
https://en.wikipedia.org/wiki/Spitting
Advisory on the wall of a building in New Orleans. Spitting is the act of forcibly ejecting saliva or other substances from the mouth. It is currently considered rude and a social taboo in many parts of the world including the West, while in some other parts of the world it is considered more socially acceptable.
https://en.wikipedia.org/wiki/Spitting
Quick Answer. Excessive saliva is caused by an increase in the body’s saliva production or a decrease in a person’s ability to swallow or keep saliva in the mouth, says Mayo Clinic. Some causes of increased saliva production include improperly fit dentures, gastroesophageal reflux disease and a mouth or throat infection. Keep Learning.
https://www.reference.com/health/cause-excess-saliva-6fec808f8be4e883
Find out the possible causes of spitting up, and what you can do about it. Spitting up is common in healthy babies. About half of all babies during their first three months experience their stomach contents coming back up into the esophagus, a condition known as gastroesophageal reflux, infant reflux or infant acid reflux.
http://www.mayoclinic.org/healthy-lifestyle/infant-and-toddler-health/in-depth/healthy-baby/art-20044329
Spitting Up in Infants Causes. When we eat or drink, food passes down the feeding tube or esophagus and into the stomach. In the stomach, the food mixes with acids and passes slowly into the intestines for further digestion. A valve between the esophagus and the stomach helps prevent food from coming back up and out of the stomach. In infants, this valve is not well developed and can more easily allow food to go back up the feeding tube and cause spitting up.
http://www.emedicinehealth.com/spitting_up_in_infants/article_em.htm
That's what we see with anxiety and drooling, along with general excessive saliva production. Anxiety doesn't generally cause severe drooling, but it can lead to increased amounts of saliva that is caused not directly from anxiety, but from a separate symptom of anxiety.
http://www.calmclinic.com/anxiety/symptoms/drooling
Dry mouth and Thick saliva or mucus. WebMD Symptom Checker helps you find the most common medical conditions indicated by the symptoms dry mouth and thick saliva or mucus including Dehydration (Children), Dehydration (Adult), and Sjogren's syndrome. There are 11 conditions associated with dry mouth and thick saliva or mucus. The links below will provide you with more detailed information on these medical conditions from the WebMD Symptom Checker and help provide a better understanding of causes and treatment of these related conditions.
http://symptomchecker.webmd.com/multiple-symptoms?symptoms=dry-mouth%7Cthick-saliva-or-mucus&symptomids=85%7C233&locations=7%7C7
what causes spit
A valve between the esophagus and the stomach helps prevent food from coming back up and out of the stomach. In infants, this valve is not well developed and can more easily allow food to go back up the feeding tube and cause spitting up. In infants, a valve between the esophagus and the stomach is not well developed and can more easily allow food to go back up the feeding tube this causes spitting.