Hi, Are you feeling generalized senstivity in all the teeth or localized senstivity in some areas? Generalized is suggestive of problem with gums. Gums inflammation may be due to plaque or calculus deposition or due to improper brushing. It exposes roots of teeth which causes senstivity to hot and cold. Brushing twice a day with soft brush and in upside down fashion with warm saline rinses is good for oral hygiene. Localized senstivity or pain may be due to decay or loss of enamel. Visit a dentist for oral examination so that we can check for cause of senstivity and cure it.

Sensitivity may be due to A) Cavity in one of the teeth, which can be easily filled up and make your problem go away or B) Due to your enamel getting worn off, either due to hard brushing or clenching teeth, etc, in which case you might benefit from sensitivity toothpastes. Best is to visit a dentist, and rule out a cavity - if there is a cavity and you do not get it filled soon, maybe that tooth will become painful all the time later on.