In the West, beri-beri strictly refers to a particular ailment that is caused by a deficiency of thiamine (vitamin B1).
In the Philippines, the word manas has also come to have a colloquial meaning.
Say you pinch a large portion of someone's skin for more than a few seconds.
This usually causes a discoloration near the surface.
Some Filipinos will call that manas.
Say you're wearing shorts and sitting down, you cross your legs. After a few minutes, when you uncross your legs, the skin on your thighs will have patches of red and white because of the blood that accumulates. Ay, nagmanas. (Oh, it went manas.)
It is thought that the fatter a person is, the more prone he or she is to manas. Pregnant women complain about it.
Swelling of the limbs, especially of the lower legs, is a symptom of beriberi.