Is phlebitis permanent?

No: No but depending on cause and location they can recur. The deep vein phlebitis or DVT can become chronic and end up with vein wall damage and swelling.

No: Phlebitis is inflammation in a vein usually caused by a clot (thrombophlebitis). These will resolve and the pain will go away. Sometimes the clot will destroy the vein permanently but in general this si not a significant problem unless it is in the deep veins.

No : But its effects can be long lasting. Often what happens is that the pain, swelling, warmth, redness and inflammation go away but some residual scar is left in the vein. This can lead to further episodes of phlebitis later on, or it might never bother you again.