Found these strange bubbles forming under the paint on my wall near the floor. They feel soft to the touch and seem to be getting bigger—is this a reaction to humidity or something worse?

tide mark on the lower part of the wall, salt deposits, or a musty smell, which are telltale signs of rising damp.

Measuring the moisture content at different heights of the wall using a moisture meter can confirm rising damp, with higher moisture content closer to the floor.

Improper surface preparation before painting can lead to poor adhesion and subsequent bubbling. This includes failing to clean the surface, not allowing it to dry completely, or applying paint in unsuitable conditions.

Using old paint or low-quality paint can also result in bubbles, as can the presence of vapor barriers on the warm side of wall insulation, which can trap moisture and cause it to condense.

Perform a simple moisture test by taping a piece of aluminum foil to