I have a ton of these things. I used to think they were inflamed and knotted muscles, but my massage therapist tells me otherwise. I have a hard time telling which lumps are lipomas and which ones are myofascial trigger points, especially since most of them are in my back, so I'm not sure if any of mine are painful.
Humidity. The most common cause of condensation on double-glazed windows is humidity. The outside window is colder than the inside window causing fog or frost to build up in-between the two panes. The window and house is extremely airtight and cannot breath.
Window condensation is an especially difficult problem to solve with double-glazed windows. When moisture builds up between the inside pane and outside pain, it cannot be cleaned by conventional methods such as window cleaner and paper towels.