What causes coldness, changes in skin color, and swelling of the lower legs?

Coldness, changes in skin color, and swelling of the lower legs can be attributed to circulatory system changes. When circulation is compromised, it affects blood flow to the extremities, which can result in varying symptoms, including cold skin, discoloration (such as paleness or bluish hues), and swelling due to fluid accumulation. This often occurs in conditions such as peripheral artery disease, venous insufficiency, or blood clots.

In contrast, while infections can lead to swelling and changes in skin color, they are typically accompanied by other symptoms like fever or redness and warmth at the site of infection. Muscle strain primarily results in localized pain and discomfort but does not usually cause coldness or a change in skin color. Neurological disorders can result in some symptoms related to circulation, but they are more associated with changes in sensation and muscle control rather than direct changes in circulatory functions affecting temperature and color. Thus, circulatory system changes are indeed the most accurate cause of the described symptoms.