Haematoma

A localized collection of blood (usually clotted) that is caused by bleeding from a ruptured blood vessel. Haematomas can occur almost anywhere in the body and vary from a minor to a potentially fatal condition. Less serious types of haematoma include haematomas under the nails or in the tissues of the outer ear ( cauliflower ear). Most haematomas disappear without treatment in a few days, but if they are painful they may be drained. More serious types include extradural and subdural haematomas, which press on the brain (see extradural haemorrhage; subdural haemorrhage).