With coma-like deep sleep you are sleeping - you are not in a coma. There are major differences between a coma and a deep sleep.
Defining a Coma
A coma is a long state of unconsciousness during which a person appears to be sleeping and does not respond to their environment. The medical community uses very specific parameters when defining a person in a coma. A person with a coma:
- Is unconscious
- Cannot be awakened
- Does not have sleep cycles
- Does not respond normally to light or pain
A coma is not a disease. It is a response to an injury to the brain, a seizure or a metabolic problem in the brain. It can be temporary and last up to four weeks, or it can be permanent. More than half of the people with comas had a trauma to the head, a problem in the brain's blood circulation system or a medical problem such as:
- Bleeding or swelling in the brain
- Infections in the central nervous system
- Oxygen deprivation
- High blood sugar levels
- Toxin build-up
Comas Are Not Deep Sleep
The word coma comes from the Greek word koma which means deep sleep. This has caused many people to believe that a coma is somehow related to a deep sleep. This is not true. According to Dr. Chris Idzilowski, the Director of the Edinburgh Sleep Centre, a coma is very different from deep sleep. During a coma, the brain is disorganized in the way it functions and responds. Each coma patient can have a different levels and types of brain functions. In general, with a coma patient, some parts of the brain might still be working; however, most parts have shut down and the brain is no longer able to process information.
This disorganization of the brain functions is very different from during deep sleep. In deep sleep, the sleep systems are very organized. Some parts shut down, while others keep working. As the person passes through the different sleep cycles, the organization will change. For example, your brain may be shut down to the outside world and not respond to light or sound but still be aware of dreams.
Coma-like Deep Sleep: Is it Possible?
When people refer to a "coma-like deep sleep" they are usually referring to a person being in a deep stage of sleep, sometimes called "deep sleep" or "Stage Four" sleep. This is the stage when your body and mind totally relaxes. The brain waves become very slow and all eye and muscle movements stop. During this stage of sleep a child may experience bedwetting and a child or adult may experience sleepwalking or night terrors.
It is very difficult to wake someone up while they are in deep, Stage Four sleep. They have a hard time becoming aware of their surroundings. They may feel disoriented and groggy for a few minutes after they have been awakened. If they have an aggressive sleep personality, they might become very vocal or physically try to resist waking up.
The sedative properties in some over-the-counter sleep medications can cause a person to sleep in what appears to be a very deep sleep. The person may have very limited movement during sleep and may be very difficult to wake up. They may feel as though they have had a deep sleep, when in reality their limited movements while sleeping may be due to the effect of the medication on their nervous system, not to their entering deep, Stage Four sleep.