First run a piece of paper at the bottom of door to identify where is sticky.
Stop door scraping floor.
Use a screwdriver to tighten the screws in the top hinge on the door and frame.
There is also a planer attachment for the dremels which works pretty well for light jobs and in some cases you can even do it without removing the door.
You may use a drill with a screwdriver head attachment but you need to be careful not to overdrive the screws and break or strip them.
The dragging door corner can scrape the floor or threshold underneath the bottom of the door which can tear vinyl floors and scratch wood floors.
If you recently installed carpet or a new floor then you will need to plane the bottom of the door with either a hand planer or by sanding.
If it does tighten the hinge screws with a ratcheting screwdriver.
Check to see if this relieves the rubbing.
Use a pencil or a label to mark where you need to sand down.
You can get rid of the annoyance of lifting a.
Lift the door by grasping both handles and gently putting upward pressure.