However it is not necessarily related to a patient's weight and can occur even in very thin individuals. This buildup can get calcium
deposited in it as well, which makes it stiff, hence the term "hardening of the arteries". The cyst behind your knee sounds like it may be a separate issue, called a "baker's cyst
". We get these cysts behind our knees for no apparent reason. They swell and sometimes can rupture
. They often however cause no problem. They are usually identified on an ultrasound study. If you had worsening pain, redness, leg pain
, or new symptoms then it would need to be immediately evaluated.