Obtundation is mild to moderate alertness reduction (altered level of consciousness) with decreased interest in the environment and slower than normal reactivity to stimulation.
[citation needed] It is distinguished from the much stronger states of unresponsiveness of stupor and coma.
[1] There is a wide range of potential causes including head injury, interruption of blood circulation, impaired oxygenation or carbon dioxide toxicity (hypercapnia), central nervous system (CNS) infections, drug intoxication or withdrawal, post-seizure state, hypothermia, and metabolic derangements such as hypoglycemia, hyponatremia, and hypercalcaemic crisis.
[2] Symptoms include delayed reaction time, lessened interest in the environment, very short attention span, and excessive sleeping.
[3] The root word, obtund, means "dulled or less sharp" (cf.