An intramuscular haematoma is when the muscle fascia ('casing') does not let the blood escape so it stays in the muscle longer often increasing pressure in the muscle. Swelling and pain generally lasts more than 48 hours.
'Intra' -'within' and 'haematoma'='a confined lump of blood', so an intramuscular haematoma is bleeding within the muscle tissues.
An intramuscular haematoma is when the muscle fascia ('casing') does not let the blood escape so it stays in the muscle longer often increasing pressure in the muscle. Swelling and pain generally lasts more than 48 hours.