Leg blood clots are not that rare. They form if you are a frequent traveller who spends too much time immobile. Buses and planes cannot be avoided and you are to spend a few hours in cramped spaces.
If you have an opportunity to stretch your legs or walk around, you are lucky. If you stay immobile, do not be surprised to find out that you have blood clots in your legs.
Swelling is especially bad if it causes pain. The pain is felt at the area of the clot. Have a look at your legs and see if there are any changes. Touch the most suspicious sites. The most common areas where blood clots tend to form are ankles and calves. These two areas have tissue and bone densities, this is why your body can hardly clear a clot in a natural way. Not all swellings are clot-related. If it is clot-related, you will notice that neither cold nor hot compresses resolve the issue. Sometimes such swellings intensify without any reason or external injury to the affected area.