See your painting as the artist intended.
At Art Restoation Studios the following are some of the terms used for typical issues in customers work.

Abrasions and Tears. Where the painting has been damaged.

Aligatoring. Caused by expansion and contraction of the paint layers from temperature fluctuation.
Bitumen Blistering. Bitumen was used frquently throughout the 18th and 19th century to enhance the darks.

Blanching and Bloom. A lightened or whitish area in a paint or varnish layer, caused by light being defracted.

Crumbling. A friable paint layer that has broken down into small pieces.

Cupping. The formation of small concavities or cup like hollows in the paint layer.

Craquelure. A network of cracks caused by ageing. Thought to be acceptable in antique paintings.

Delamination.

Foxing.

Insect Secetions.
Lifting.

Tenting.
In extreme cases it may be neccessary to apply a facing of Japanese tissue and fish glue to stabilize the surface prior to addressing any of the above issues.