Bumps on record surface

Hello,
I am have some records that having small bumps (i.e.bubble like raised up areas) on records' surface. Will that affect the music data stored inside the track? How does it happen and prevent it?

Thank You
Kevin

I need more information. What kind of record? How big are they? Did they appear, or were they always there?

I Have a 78 Rpm Copy Of The Fresandos,Your Last Goodbye On Star X 501 Mint- Copy,But It Has Many Tiny Bumps On It,But It Plays Perfect.I wonder if they are pressing defects

Bumps on a record surface shouldn't be a problem if you are using a good needle and appropriate tracking weight. Of course, if they are huge bumps and don't allow the needle to track under any kind of weight, then yes, pitch the record. But I've never seen a record like that.

I just hope it isn't the record surface separating from a substrate. Some records made during World War II and later had good shellac laminated on a cheap substrate, to save shellac. I have one that has fallen apart.