The first thing you need to do is to distinguish between simple leg soreness and swelling, or a combination of lower limb edema. If it is just sore legs, then it may not be a big problem, it may be related to overexertion or poor vascular reflux in the lower limbs, so you should pay attention to rest and avoid overexertion, and you can soak your feet in warm water every night to relieve the sore legs. However, if edema of the lower extremities is also present, it is necessary to pay attention to it, because systemic diseases of multiple systems may cause edema, such as edema when the heart is not functioning well, and edema when the liver, kidney or thyroid gland has problems. The cause of edema should be clarified by screening blood and urine tests, liver and kidney functions, thyroid function tests, cardiac function tests, ECG, and cardiac ultrasound.