Exposure to high concentrations can lead to a serious condition known as fluorosis. Fluorosis is primarily categorized as skeletal and dental fluorosis, but it leads to other severe complications as well.
Dental Fluorosis. When severe, tooth stains turn yellowish brown to black, and the teeth start pitting.
Skeletal Fluorosis. In the advanced stage, fluoride deposits in joints of the neck, knee, pelvic, and shoulder bones make it difficult to move or walk. Symptoms include joint pain, back stiffness, burning sensation, tingling in limbs, muscle weakness, and chronic fatigue.
Other Issues. Excess fluoride leads to liver, kidney, digestive and respiratory issues.