<s>[INST] I was walking through the woods and the left side of my shin bone hit a branch and it left a red mark then slowly within the next 45 minuets it started swelling into a ball and turned a little purple. It s not completely on the bone but most of it is. It s rather squishy to touch and the swollen ball turned into a huge bump on my leg. It s slightly red and a little black after 5 hours. [/INST] Hi Thanks for your question.Brief answerHaematoma due to injuryDetail answerYou have injured the soft tissue envelope over your shin bone, leading to a hematoma formation.You need to apply ice compresion. use crepe bandage.Thanking you regards </s>