If you are familiar with Telenovela, Hollywood, Bollywood, or Nollywood movies (including movies from any part of the worrld where you are), you must have seen scenes where people fall into a coma, possibly after an accident, and their love ones will spend days, months, or even years with them with the aim of trying to call them out of the hibernating world to the world of living people. They will sing for them, play their favorite songs, read to them, and so on with one thing at heart; to bring them back to consciousness.
While a lot of people have come out of a coma, there has been no definitive way to treat it despite our advancement in technology and knowledge of science. While the origin of the word Coma means deep sleep, it is completely different from sleep. It is a form of unconsciousness where the person is unable to respond to external stimuli. While people who are asleep can wake up when they hear the smallest sound around them, people who in a comatose state would not wake up even if the loudest music is played beside them.
In the past doctors have tried numerous things including shocking patients to consciousness, blood letting, emptying the stomach, an so on, but this forms of treatment didn't help in anyway. One thing that movie directors are correct about is that a person can go into coma as a result of a serious accident leading to trauma which causes the brain to shut down so as to be able to repair itself but then, coma can be induced by doctors in the hospital.
When patients are placed on medically induced coma, it is because they are at a high chance of suffering a brain damage as a result of trauma, drug overdose, or a disease. When the brain is traumatized, there is a possibility of experiencing a swell, or edema which could cause it to push against the skull. This can leave the brain starving of oxygen. With medically induced coma, the electrical activities of the brain is reduced and the brain's metabolism slowed down. Asides from accidents and induced coma, coma can be caused by stroke, drug or alcohol abuse, diabetes, and a brain tumor.
flickr
While a coma would normally last just as few days, it can extend to weeks, months, and they can even enter into a vegetative state where their chances of coming out becomes very low. People who are lucky to come out of a coma can end up with major or minor health issues such as speech impairment, inability to coordinate movement, and mental retardation.
When a person is in a vegetative state, they can make physical movements such as grunt but there is no reaction to external stimuli exerted on them which means that the movements are involuntary. Catatonia is a coma where there is not type of movement or response to any kind of stimuli. This type of coma can usually require the help of a machine to breath and pump their heart. When people experience Stupor, they have the ability to be awake but with little effort and even while they can fall into deep unconsciousness, they can still survive.
While there is no treatment for it yet, scientist have confirmed that when a person is in a coma state, the brain is trying to repair itself. People who fall into coma can suffer muscle atrophy, as a result of the muscles not moving. They can also suffer from pressure ulcers also known as Bedsores as they are immobile and unable to feel pain. One good news about coma is that most people who get into coma recover in few weeks at least to a reasonable extent.
Reference
https://www.bustle.com/p/what-happens-when-youre-in-a-coma-your-body-reacts-in-strange-ways-when-your-brain-function-shuts-down-3067212
https://www.nhs.uk/conditions/coma/
https://academic.oup.com/brain/article/131/3/877/317052
https://www.hopkinsmedicine.org/healthlibrary/conditions/dermatology/bedsores_85,P00260
https://www.ncbi.nlm.nih.gov/books/NBK430722/
https://www.mayoclinic.org/diseases-conditions/coma/symptoms-causes/syc-20371099
https://www.livescience.com/39483-what-is-a-medically-induced-coma.html