Hello, thanks for the query.
Due to long use of vein ( 2 days) as for infusion for drips there became haematoma
of vein that's subsides.
Due to some inflammatory drugs there developed thrombophlebitis
& superficial thrombosis
of this vein so there is pain.
If you feel the the rout of vein with the palm of your hand you will feel some hardness over this vein and that is thrombophlebitis.
Iced sponging and rubbing of heparin
ointment will give you complete relief.
Still you will not get complete relief than consult a doctor and get an advice at once.