Chewing tobacco, also known as 'smokeless' or 'spit' tobacco, can be detrimental to the health of the user in numerous ways. Generally, a pinch or wad of this substance is inserted in between the cheek and teeth, between the lips and gums, or below the tongue. There, tissue-irritating tobacco juices containing nicotine and at least three known carcinogens may maintain contact with the mouth surfaces for extended periods. This may explain why smokeless tobacco use, especially in the form of snuff, seems to correspond to the incidence of many oral diseases, including cancers of the mouth, pharynx (FAIR-inx), larynx (LAIR-inx), and esophagus, gum recession, accelerated tooth abrasion and decay, and potentially malignant white intra-oral skin patches called leukoplakia (loo-koh-PLAY-kee-ah). Resulting dental complications may include discolored teeth, bad breath, exposed teeth root surfaces, erosion of jawbone support, and even loss of permanent teeth. Smokeless tobacco has also been found to contain potentially dangerous levels of heavy metals such as lead and cadmium (KAD-me-um), which can affect fetal health. There seem to be significant health consequences related to the high nicotine exposure as well. Since nicotine can elevate blood pressure, heart rate, and blood cholesterol, ongoing smokeless tobacco use may increase the risk of heart disease, vascular disease, peptic ulcers, and fetal complications, as do cigarettes. Also, such levels of nicotine usually produce psychological effects such as relaxation, arousal, and euphoria, making smokeless tobacco potentially addictive. Therefore, it's often used in increasingly higher quantities, multiplying the risk of all the associated adverse health conditions.