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.
Condensation is responsible for ground-level fog, for your glasses fogging up when you go from a cold room to the outdoors on a hot, humid day, for the water that drips off the outside of your glass of iced tea, and for the water on the inside of the windows in your home on a cold day.