Thank you for your query.
48 beats/min is less heart beat than normal.
Heart rate usually tends to increase during exertion or exercise.
or less heart beat has many causes.
Among them the common causes are athlete, heart block
, intracranial space occupying lesion, obstructive jaundice
So an ECG & some relevant investigations are needed to exclude the causes.
It is better to consult with a physician to get examination.