An altered mental status or level of consciousness requires determining the underlying cause. The initial approach involves assessing the ABCs, giving supplemental oxygen, checking glucose, and looking for signs of infection, trauma, or drugs. Further evaluation includes detailed history, physical exam focusing on vital signs and neurological status, and diagnostic testing of blood and imaging based on suspected etiologies like metabolic derangements, medications/toxins, infections, and structural brain issues. Treatment is directed at reversing or controlling the specific cause, such as treating seizures, lowering blood pressure in hypertensive encephalopathy, or giving antibiotics for infections.