Hypoglycemia: This condition is a common and easily treatable cause of altered mental status, including difficulty arousing a patient. It can occur in anyone, especially in diabetic patients who may have taken too much insulin or skipped a meal.

Sleep Deprivation: Lack of sleep can significantly impair cognitive function and make a person difficult to arouse.
Medication Overdose or Side Effects: Many medications, especially sedatives, antidepressants, and antihistamines, can cause drowsiness or altered mental status as a side effect or in overdose.
Infection or Sepsis: Severe infections can lead to altered mental status due to the systemic inflammatory response.
Traumatic Brain Injury: Head injuries can cause varying levels of consciousness, including difficulty arousing the patient.

Stroke or Cerebral Vasculitis: Although less common, these conditions are critical and require immediate intervention. Altered mental status can be a presenting symptom.
Meningitis or Encephalitis: Infections of the brain and its membranes can present with altered mental status, fever, and other neurological signs.
Status Epilepticus (Non-convulsive): Prolonged seizure activity without overt convulsions can cause a patient to be difficult to arouse.
Carbon Monoxide Poisoning: This can cause altered mental status, including coma, and is often associated with exposure to combustion products in enclosed spaces.

Wilson's Disease: A genetic disorder that leads to copper accumulation in the brain and liver, which can cause neurological symptoms including altered mental status.
Hashimoto's Encephalopathy: A rare condition associated with autoimmune thyroiditis, characterized by altered mental status and neurological symptoms.
Wernicke's Encephalopathy: Caused by thiamine deficiency, often seen in alcoholics, leading to confusion, ataxia, and ophthalmoplegia.
Prion Diseases (e.g., Creutzfeldt-Jakob Disease): Rare, fatal brain disorders that can cause rapidly progressive dementia and altered mental status.