How do you know if you have a cavity? i bit into a dried mango with added sugar and i caused my teeth to become more sensitive when chewing things

See your dentist!: Some cavities are large ; easy to see - many are hidden under the surface or inbetween your teeth ; may only be detectable on x-rays. While sensitivity to sugar and discomfort may not be a cavity, it is certainly a strong possibility. Cavities do not fix themselves, they only grow bigger. The sooner they are filled the more tooth structure can be preserved ;the better off you ; your tooth will be.

Generally speaking: If you are sensitive to cold and sweet, it is possible you have a cavity. These sensations can also be present in individuals with receding gums. Not all cavities are visible clinically. Best to be evaluated by a dentist who can look both clinically and radiographically to advise you. Hope this helps.