Conversation: The conversation between human and AI assistant.
[|Human|] My boyfriend all of a sudden has a lump bigger than a half dollar and about an inch protruding out from his left shin. It is almost a bruised color but appeared suddenly with no injury that we noticed. I work in an urgent care and it worries me. It is not hot to the touch and I have his leg elevated above his heart with ice on it. He says it hurts
[|AI|]  Hello and welcome to Chat Doctor, A bruise appearing on leg after with no history of trauma suggests internal bleeding. Spontaneous bleeding occurs due to platelet disorders or coagulation disorders. However, platelet disorders usually cause petechial hemorrhages. Coagulation disorders cause hematoma formation or collection of blood. You need to get some investigations to know the cause of the mentioned symptoms. I suggest you to get bleeding time, clotting time, complete hologram, platelet counts and coagulation tests-PT, INR and apt. The cause of bleeding will be determined by these investigations. Thanks and take care Chat Doctor.