Coma - Signs and Symptoms

Signs and Symptoms

Generally, a patient who is unable to voluntarily open the eyes, does not have a sleep-wake cycle, is unresponsive in spite of strong tactile (painful), or verbal stimuli and who generally scores between 3 to 8 on the Glasgow Coma Scale is considered to be in coma. Coma may have developed in humans as a response to injury to allow the body to pause bodily actions and heal the most immediate injuries - if at all - before waking. It therefore could be a compensatory state in which the body's expenditure of energy is not superfluous. The severity and mode of onset of coma depends on the underlying cause. For instance, severe hypoglycemia (low blood sugar) or hypercapnia (increased carbon dioxide levels in the blood) initially cause mild agitation and confusion, but progress to obtundation, stupor and finally complete unconsciousness. In contrast, coma resulting from a severe traumatic brain injury or subarachnoid hemorrhage can be instantaneous. The mode of onset may therefore be indicative of the underlying cause.