Treatment varies depending on the cause. When damage has occured, bleeding in the brain, swelling and congestion of the damaged tissue is pressent. In extreme cases, brain swelling is so great that portions of the brain must be forcible squeezed out of the skull. An alternative to squeezing portions of the brain out of the skull is to saw off the skull and place it in a cold storage to better accommodate the swollen brain. There are different stages of a coma.
Most people believe that a person in a coma is in a deep sleep.
This is not entirely true. Some stages of coma resemble a deep sleep but not all. The progress of coma is measured by the patient's increasing awareness of external stimuli. There are many levels of coma which the patient will pass through as functionality increases. Depending on the stage, a person in a coma may make movements, sounds and experience agitation.