Contusion is as a result of bruises and it happens when an injured capillary or blood vessel leaks some amount of blood into the surrounding area. Contusions are a type of hematoma, which refers to any collection of blood and can be associated with multiple microhemorrhages, small blood vessel leaks into brain tissue. Contusion is common in 20–30 percent of severe head injuries.
If you have one sickle cell gene, you have sickle cell trait and you will not develop the sickle cell disease. If you inherit two sickle cell genes, you have sickle cell anemia.