<s>[INST] My dog jumped on me play and scratch my arm. Very small scratch but underneath where he got me is on top of a vein. About an hour after it happened I noticed a lump underneath skin about the size of a nickel in circumference and raised up about half inch and starting bruise. [/INST] Hi,Welcome to HealthcareMagic .That is due to small haematoma. It will heal by itself in few days once blood gets absorbed.If pain is there you may take anti inflammatory drug like aceclofenac.Hope I have answered your query. RegardsDr Deepika Patil </s>