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Disorders of Consciousness

Medically reviewed by Last updated on Oct 3, 2022.

What is a disorder of consciousness (DoC)?

A DoC is a condition that causes problems with being awake, aware, or both. The person may not be aware of himself or herself, or of the environment. It also may not be possible to wake or rouse the person. A DoC can range from mild to severe and can be temporary or permanent. Some DoCs can go away and then return.

What are the types of DoC?

Healthcare providers will do brain and nerve tests to check the person's responses, such as reflexes. The amount of response can help providers understand what kind of DoC the person may have. If no eye or body movement is seen, providers may check the person's response to sound or touch. The person may shift between the following states of consciousness:

  • Stupor means the person has brief periods of consciousness. This happens when he or she is wakened, such as by a touch. The person may be able to open his or her eyes or look around but will quickly go back to a sleep state.
  • Minimally conscious state means the person can do small movements on purpose. An example is following an object with his or her eyes. He or she may be able to move an arm or leg when asked to, answer yes or no, or talk a little.
  • Vegetative state means the person is awake but not aware of himself or herself, or the environment. His or her eyes may open and close regularly over 24 hours. He or she may go through a sleep-wake cycle. Movement is from a reflex (automatic reaction) and is not done on purpose. Vegetative state may also be called post-coma unawareness of unresponsive wakefulness syndrome.
  • Coma means the person is in a deep state of unconsciousness. He or she does not respond and cannot be woken by anything such as a voice, touch, or pain.

What causes a DoC?

  • An injury can damage part of the brain that controls consciousness. The injury can be traumatic, such as being hit in the head. It can also be non-traumatic, such as a stroke or swelling in the brain from an illness.
  • Degenerative disorders are progressive brain conditions, such as Alzheimer disease. These brain conditions cause brain cells to slowly die and can also lead to a DoC.
  • Lack of oxygen can damage or kill brain cells. Consciousness may be affected when blood flow to the brain, or part of the brain, is stopped. This may happen during a stroke, or when there is severe bleeding or swelling in the brain. A brain tumor may push some parts of the brain and affect its blood vessels. Seizures, a heart attack, or lung problems may also decrease oxygen to the brain.
  • An electrolyte imbalance can affect brain function. Salt, potassium, and magnesium are examples of electrolytes. An imbalance may happen if the person loses too much body fluid, such as through vomiting or heavy sweating.
  • Medicines, drugs, or alcohol can affect consciousness or prevent the brain's normal activity.
  • Other conditions or diseases can cause the body to make chemicals that are toxic to the brain. Examples include kidney or liver disease. If the person has diabetes, extremely high or low blood sugar levels can cause a diabetic coma.

How is a DoC treated?

The cause of the DoC may be treated. If the cause is not known or cannot be treated, effects of the DoC may need to be treated:

  • Medicines may be given to correct an electrolyte imbalance, control high blood pressure, or stop seizures. Antibiotics may be given to treat a bacterial infection. Medicine the person was taking may be stopped or changed if it is causing the DoC. An example is insulin or other diabetes medicine.
  • An IV or nasogastric (NG) tube may be used to give the person nutrition and liquids. An NG tube is put in through the nose and goes down into the stomach. The tube may also go directly from the outside of the body into the stomach. This is called a gastrostomy tube.
  • Extra oxygen may be needed to help the person breathe easier. He or she may need a ventilator. This is a machine that can breathe for the person if he or she cannot breathe well on his or her own.

What do I need to know about recovery from a DoC?

Recovery may also be called emergence. The person may emerge (become) conscious in stages. The ability to recover and the speed of recovery depends on what caused the DoC.

  • Emergence often happens gradually. The person may not suddenly wake up and be aware. He or she may show small signs, or move between being conscious and unconscious.
  • Healthcare providers will look for certain signs. The person may start to respond each time providers tell him or her to move. They will also see if the person can use at least 2 objects correctly.
  • The amount of time the DoC lasts can affect recovery. A DoC that lasts longer than 28 days can be more difficult to recover from.

What can I do to help the person?

  • If possible, give the person's advance directive to healthcare providers. This is a legal document that explains the person's wishes for extended medical care if he or she cannot tell providers.
  • Talk to providers about care options. The person may need to be moved to a facility that can provide ongoing care. This may be needed if the DoC continues for 28 days or longer. You may need to check the person's health insurance to see what kinds of care are covered. You may be able to visit possible facilities and help choose one. The person may be cared for at home. This depends on the kind of DoC the person has, and the help that will be available at home.
  • Set up medical equipment if needed. If the person will be going home, he or she may need medical equipment. Examples include a hospital bed that adjusts, or a lift device. He or she may need a wheelchair or walker, or grab bars installed through the home. An occupational therapist can help you make a list of items the person may need at home.
  • Learn how to care for the person's physical needs. You can learn how to use and care for certain kinds of equipment, such as a feeding tube. Providers can teach you how to move the person's arms and legs. This prevents stiff joints and muscles, and prevents pressure injuries. Skin and mouth care can prevent infections and other health problems. You may also be able to learn bowel or bladder care.

Care Agreement

You have the right to help plan the person's care. Learn about his or her health condition and how it may be treated. Discuss treatment options with the person's healthcare providers to decide what care he or she will receive. You always have the right to refuse treatment.The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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Further information

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