The condition of swollen legs with a pit when pressed belongs to lower limb edema, which is in a more serious state. Lower limb edema can be divided into three grades. Mild edema occurs below the eyelids and orbits, or in the ankles and palms of the feet, where there is a mild depression after pressure, and it disappears quickly. Moderate edema is a partial edema below the knee, with a deeper depression after pressure and a slower recovery. Severe edema is a generalized edema, with shiny skin and even leakage of body fluid, and may be accompanied by problems such as peritoneal effusion. Most of the lower limb edema is due to kidney function or cardiovascular problems, and it may also be caused by pathological changes in the blood vessels of the lower limbs, such as varicose veins and venous thrombosis in the lower limbs, which can lead to lower limb edema.