<s>[INST] Hi, My dad had a blood test done in his arm and he didn t press on it when the nurse said. Since then he had some bruising on the sight. Then developed a with flattish lump in the clevis of his arm. His arm was very weak and ached a lot. This was about 2 weeks after the blood test. Then he woke one morning and it was like the lump had burst and was gone and so was the pain, but he had a massive bruise above the sight from his elbow joint to his shoulder. The bruise was very dense. Can you explain this?Cheers Glenys [/INST] There was a collection of blood around the puncture site (haematoma ). That haematoma got burst with drainage of blood and there was seepage of blood along the course of vein causing discolouration. </s>