Possible causes of Change in behavior

57 conditions can cause this symptom. Most common are listed first.

• Alcohol withdrawal syndrome Common Urgent
• Alzheimer's disease Common
• Carbon monoxide poisoning Common Urgent Pediatric
• Cerebral vascular accident (stroke) Common Urgent
• Dehydration Common Urgent Pediatric
• Dementia (impaired cognitive function) Common
• Diabetic ketoacidosis (DKA, a complication of poorly controlled diabetes) Common Urgent Pediatric
• Drug overuse Common Urgent
• Epidural hematoma (bleeding outside of the brain or spinal cord) Common Urgent Pediatric
• Hypoglycemia (low blood glucose) Common Urgent Pediatric
• Hyponatremia (low blood sodium) Common Urgent
• Hypothyroidism (low thyroid hormone) Common
• Hypoxia (lack of oxygen) Common Urgent Pediatric
• Intracranial hemorrhage (bleeding in brain) Common Urgent
• Meningitis (brain spine infection) Common Urgent Pediatric
• Respiratory failure (breathing failure) Common Urgent Pediatric
• Seizure (epilepsy) Common Urgent Pediatric
• Subdural hematoma (bleeding on brain) Common Urgent
• Anemia (low red blood cell count)
• Hepatic encephalopathy (liver failure confusion) Urgent
• Hydrocephalus (fluid on the brain) Urgent
• Lewy body dementia
• Meningioma (brain tumor)
• Porphyria
• Adjustment disorder
• Alcohol (ethanol) intoxication
• Alcoholism
• Altered mental status (confusion) Urgent
• Anxiety disorder
• Attention deficit hyperactivity disorder (ADHD)
• Benzodiazepine (Valium) overdose Urgent
• Bipolar affective disorder (bipolar depression)
• Blood loss Urgent
• Cerebellar syndrome
• Cocaine abuse Urgent
• Depression (excessive sadness) Urgent
• Drug reaction
• Dysthymia (neurotic depression)
• Environmental exposure (cold, hypothermia) Urgent
• Hemolytic anemia Urgent
• Major depressive disorder (severe depression) Urgent
• Malignant hyperthermia (high temperature) Urgent
• Marijuana abuse
• Medication reaction Urgent
• Menopause
• Multiple sclerosis (MS)
• Narcotic (morphine, heroin) abuse
• Obsessive compulsive disorder (OCD)
• Panic disorder
• Personality disorder
• Phobias (irrational fear)
• Post-traumatic stress disorder (PTSD)
• Premenstrual syndrome (PMS)
• Prescription drug abuse
• Schizoaffective disorder
• Schizophrenia (psychiatric disease) Urgent
• Stress