The highest risk of developing blood cloths in the lower extremities after having a long surgery is within the first week after the surgery, but it can last for 4 to 6 weeks if the patient does not have normal and regular activities during the day, as walking, going up and downstairs, etc. Please check with your surgeon for a more precise advice about your case.
Thank you for your excellent question. I recommend to my patients to always remain active and well-hydrated after surgery in order to minimize the risk of blood clot development. This should continue until they have returned to their normal level of daily activity which may be a series of days after a breast lift or equivalent surgery of 2-6 weeks for a tummy tuck. Talk to your surgeon about your concerns and to have recommendations tailored to your case.
Most patients are at some increased risk for about 30 days. Early post-op more frequent attention is desired -- especially if you had a tummy-tuck or other larger procedure where you might be more likely to be less active after surgery. Most people rather quickly are "up and around" enough within a week to not need to pay special attention other than to avoid prolonged sitting. This is especially important if travelling - car/train/bus/plane.