bruxism (or nightgrinding), if left unchecked, can seriously ruin your dentition!
the only way to prevent damaging your teeth is to wear a rubberized mouthguard while sleeping!
picture shows a senior citizen patient of mine who has been a nightgrinder for a VERY LONG TIME. despite me making a nightguard for him around 2013, he said he hasn't been wearing them when i asked him last April 2017 :(
as can be seen on the picture, patient's remaining lower teeth shows excessive wear and flattening of the bite surfaces. the lower left canine even shows pulp exposure!! though the patient said he isn't feeling any sensitivity there. on the other teeth, the layers of enamel and dentin can be seen clearly.
nobody really knows why bruxism happens or why it occurs at all. but what matters is the damage that it can potentially cause to your teeth or even the jaw muscles.
so if you have a bunkmate where you live, ask them if they can hear you grinding your teeth at night :)