Swelling. The most common is swelling but pain and discomfort can also be a sign of dvt. The most important thing to remember is that if you have any concerns about having a DVT then you should have an ultrasound.
See below. Usually blood clots in the lower extremities will cause swelling and pain. There may be redness. If the toes and forefoot are pulled up towards the knee cap, there may be significant pain in the calf of the leg. Of course, there may be not symptoms. A physician or trained person may be able to palpate a rope like cord in the calf. This is a serious medcial condtion and should be seen immediat.