Dear Sunbee, hello
Thanks for writing your query.
You have not mentioned your complete details like your age, gender, whether you are on any medicaton, etc.
may be due to genetic reasons and can be harmless. It is also common in females above 40 years near their premenopausal / menopausal stages due to hormonal
There are many medical conditions also which can result in night sweats. Intake or withdrawl of some medicines can also cause night sweats.
Also take care of the temperature of your bedroom and the layers of sheets on your bed as high room temperature or many layers of bedshhets can also keep your body warm and result in niht sweats.
It is advisable that give detailed personal and medical history of youself and get youself examined and investigated.
I hope this is of help to you.