Cavities DO hurt... once the nerves are exposed, cold, heat or sweets will make the tooth hurt like nothing you've ever felt before. On the other hand, getting fillings DOES NOT hurt. With modern dentistry, you feel one little pinch and then the dentist can clean and fill your tooth's cavity without you feeling a thing. And afterwards, you will feel a bit numb and your lips and tongue may feel fat, but the pain will be gone.
Getting cavities does not hurt but, filling hurts a lot. Filling is the treatment commonly used to treat cavities and it is very painful. You should avoid getting cavities and this can be done by brushing your teeth regularly. For more details, visit http://www.ehow.com/how_5458508_prevent-cavities.html.
Depends how long you let the cavity go. . .and if another cavity in another tooth begins before taking care of the first one etc. . .many health problems arise. Gingivitis, infection, gums get swollen and the gums get loose creating more area for food/bacteria into the root of the tooth. From there rotting and more cavities closer to the root/nerve of the tooth. . .one cavity or two. . .lead to big uncomfortable problems. This is just the basics.
A cavity is a result of the bacteria in your mouth digesting the food you eat and excreting acid as their byproduct. The bacteria, acids, food, and saliva combine to create plaque which then produces acid that eats a hole in the enamel. Once the cavity gets close to the nerve it the porous nature of teeth makes pain more easily felt.
It depends on the form of cavity, some are deeper (meaning closer to the nerve) and some are shallow. The shallow ones may be due to just the way your teeth grow in. My teeth and my sisters' teeth all grew in with a few cavities. I have been lucky and have only had 2 filled because of growth and they didn't hurt that bad but it wasn't pleasurable either. Tht was just because I was nervous and a little fidgety!!