• Alzheimer's disease is an illness which can cause mild to severe memory loss.
• Parkinson's disease is a genetic defect which can always result in memory loss.
• Huntington's disease is an inherited disease which can result in memory loss.
• Chemotherapy using cytotoxic drugs to treat cancer.
• Stress-related activities are another factor which can result in memory loss.
• It is also caused by traumatic brain injury, of which a concussion is a form.

See also

• Amnesia
• Memory and aging
• Memory bias