Banged the back of my leg with a car door. Got a huge bruise and thought nothing more of it. About a week later, I had a pain in my chest. I went to the doctor and he took a chest x ray. He told me to sit still and he was calling the ambulance. When I asked what was happening, he told me I had a blood clot in my lung. He also told me if the blood clot moved to my brain, it would be fatal. To make a long story short: I was placed in the hospital and put on blood thinners to dissolve the clot. After three weeks, the clot was gone and they discharged me.