Tooth sensitivity can have many causes, can affect one or several of your teeth, and may be a temporary side effect or a chronic problem. One thing is for certain, everyone wants to avoid that sharp, shooting pain. Read on to find out what may be causing your tooth sensitivity. Brushing Too Hard Applying too much pressure when you brush your teeth, or using too hard of a toothbrush, can cause tooth sensitivity by wearing down enamel and gum tissue, exposing the most sensitive parts of your teeth. Tooth Decay This is a pretty obvious culprit, and probably what most people fear when they start to feel tooth sensitivity. Visit a dentist to treat the decay, and do what you can to prevent decay by keeping up good oral hygiene.