It is not possible to generalize how long it will take for the edema of lower limbs of SLE patients to subside after treatment, which may be caused by lupus nephritis, adverse drug reaction, etc. Different causes of lower limb edema will take different time for the swelling to subside after treatment. 1. Lupus nephritis: SLE can involve renal tubules and glomeruli and cause kidney damage. Due to the decrease of renal function, patients will suffer from hypoproteinemia and proteinuria, which in turn will cause generalized edema, foamy urine, elevated blood pressure, etc. The edema of the lower limbs caused by this condition can be subsided gradually after the patient’s condition is under control. 2. Adverse drug reactions: The common drugs used in SLE are glucocorticoids such as prednisone, immunosuppressants such as methotrexate, antimalarials such as hydroxychloroquine, and non-steroidal anti-inflammatory drugs such as diclofenac, etc. Some of these drugs may have adverse drug reactions that lead to edema. Most of the lower limb edema caused by adverse drug reactions can gradually subside after stopping the medication, but it is not recommended that patients stop taking the medication without authorization. There may be other reasons for lower limb edema in SLE patients, and the time for the edema to subside cannot be determined, so it is recommended that patients go to the rheumatology and immunology department of regular hospitals for detailed consultation and follow the doctor’s instructions for treatment.