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Glasgow Coma Scale


  • The Glasgow Coma Scale (GCS) is a tool that caregivers use to measure a person's level of consciousness. It is most often used when a person has a traumatic brain injury (TBI). A car accident, fall, or being hit on the head with a hard object can cause a TBI. A TBI can injure the person's brain badly enough that he is no longer conscious (awake and aware). Caregivers use the GCS after making sure the person's airway, breathing, and circulation (blood flow) are not in danger.
  • A brain injury can damage the parts of the brain that help the person sleep and wake normally. When this happens, the injured person stays unconscious and cannot be woken. Caregivers call this a coma. The most common cause is a TBI. Other causes include medical conditions such as stroke, seizures, or diabetes. A person may be in a coma for days, weeks, months, or even years.


What the Glasgow Coma Scale tests:

The GCS measures different types of responses. A higher score means a higher level of consciousness. A lower score means a lower level of consciousness:

  • Eye opening: This response is scored on a scale of 1 to 4 points. More points are given if the person opens his eyes on his own, or after being touched. A person is found to be in 1 in 4 levels of consciousness, based on when and why he opens his eyes.
  • Verbal response: This response is scored on a scale of 1 to 5 points. Caregivers ask basic questions and give points for correct answers. Some people are unable to answer questions correctly, or they say the wrong words. Others are not able to say words at all. They can only make sounds.
  • Motor response: This response is scored on a scale of 1 to 6 points. Caregivers ask the person to move parts of his body such as an arm or leg. A person with a TBI may not be able to move his body, even if he has no other injuries. The person gets more points for moving the way caregivers ask.

How children are tested:

Children under the age of 2 years may be given a different type of GCS. This test is called the Children's Coma Scale (CCS). You may also hear caregivers call it the Pediatric Glasgow Coma Scale, or P-GCS. The CCS is used because very young children cannot speak or move as well as adults. Caregivers give points for how well the child opens his eyes by himself. They also give points for cooing, babbling, and crying sounds instead of words. Caregivers may do the CCS with a child many times while he is in the hospital. By looking at the CCS results over time, caregivers can see signs that the child is getting better.

When and how the Glasgow Coma Scale is used:

  • Caregivers give the Field Glasgow Coma Scale (f-GCS) to an injured person before taking him to the hospital. The f-GCS gives a starting number. Caregivers use this number to help them get ready for when the person arrives at the hospital. A person who has a low f-GCS score may need help with breathing, or he may need to have surgery right away. Caregivers can compare the person's f-GCS score with later Glasgow Coma Scale scores. This helps them know how well the person is improving.
  • The GCS scores can help caregivers estimate how a person will recover after a brain injury. If the scores get higher over time, there is a good chance that the person will keep improving. After a brain injury, a person may recover and have no lasting effects. Other people may have long-lasting effects, and need help with activities such as brushing their teeth, or getting dressed. Some people stay in a long-term vegetative state. A persistive vegetative state occurs when a person is alive, but not responsive to anything.

Disadvantages of the Glasgow Coma Scale:

The GCS does not work as well if caregivers cannot score all 3 parts of the test.

  • Caregivers cannot score the person's verbal responses if:
    • He drank alcohol before his injury. Alcohol may make his speech hard to understand.
    • He has an endotracheal (ET) tube in his throat to help him breathe. The ET tube makes talking difficult.
    • The person was given medicine to decrease pain or swelling. The medicine may make him too sleepy to talk.
  • Caregivers cannot score how well the person opens his eyes if his eyes are swollen shut from the injury.
  • Caregivers cannot score the person's body movements if an injury causes pain with movement, or makes the person unable to move.
  • The GCS does not check if the person can learn and remember new things. A person's ability to form new memories is important in helping caregivers predict his recovery after a TBI.

Trauma Score and Injury Severity Score:

The Trauma Score and Injury Severity Score (TRISS) is another test that is used when a person has been injured. Caregivers check the person's age, blood pressure, and how the pupils in his eyes respond to light. A person's pupils normally get smaller in light and larger in darkness. If pupils get smaller and larger correctly, it may mean the person's brain injury is not as severe. The TRISS helps caregivers plan the person's care.

Follow up with your healthcare provider as directed:

Write down your questions so you remember to ask them during your visits.

Contact a primary healthcare provider for an injured person if:

  • The person suddenly gets dizzy.
  • The person suddenly has trouble remembering things.
  • You have questions or concerns about the person's condition or care.

Return to the emergency department with the injured person if:

  • The person begins to vomit.
  • The person states that his vision is blurry, or he is seeing double.
  • The person has a wound and it starts bleeding, or the stitches come out.
  • The person is hard to wake up.
  • The person's speech is hard to understand.
  • The person's arms or legs get weak, or he says he cannot feel them.

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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.