what is cause brown spot on pillow from my mouth
These 10 facts about space will blow your mind. Brown saliva can be a sign of a number of conditions, ranging from harmless to severe. Probably the most common cause of brown saliva is the presence of nicotine. Other possible causes, however, include acid reflux or small amounts of blood in the saliva or mucus. People who use tobacco products, either by smoking or using some form of smokeless tobacco, often have brown saliva.