Hi,
My husband is a paramedic and he told me to tell you that your dad needs to go see a doctor as soon as possible. Unexplained bruises are a symptom of bleeding or clotting disorders, and bruises that do not heal are a symptom of diabetes. Both bleeding/clotting disorders and diabetes are serious illnesses that need to be treated right away. I know it's hard to get dads to go to the doctor because they want to be tough and wait it out, but it has been months and he is not better yet so he really needs to get checked out before he has more serious complications.
E
Hi
Welcome to the MedHelp forum!
One possibility is that when he fell, he did not notice the bruise in other areas. They came up subsequently. The other possible reasons are low platelet count, clotting disorders, fragile spider veins, deep vein thrombus, deficiency of Vitamin B12, folic acid, or Vit K, a liver disease or certain cancers. It could also be due to pressure urticaria. If your father is on blood thinners like aspirin or anticoagulants, then this could also be a reason.
It is difficult to comment beyond this at this stage. Do consult your doctor and get your father investigated. Hope this helps. Take care!