A pit in the left calf may be caused by varicose veins of the lower limbs, nephrogenic edema, cardiogenic edema and so on. 1. Varicose veins of lower limbs: due to the dysfunction of lower limb veins, which leads to their stasis and expansion, causing blood circulation obstacle in lower limbs, blood accumulates in veins, making body fluids oozing out, leading to edema of lower limbs, which can appear as a pit in the left calf when pressed. 2. Nephrogenic edema: Nephrogenic edema is a common symptom of glomerular disease, due to water and sodium retention in the body caused by renal disease, which can cause edema in different parts of the body, especially in the lower limbs and face. 3. Cardiogenic edema: cardiac insufficiency can lead to venous stasis all over the body, so that body fluids accumulate in the tissue space and cause edema, especially in the low-hanging part of the body. The symptoms of a pit in the left calf can not be clearly identified as the cause of the disease, and it is necessary to improve the auxiliary examination and make a clear diagnosis for targeted treatment.