6. Head Trauma and Amnesia
Head trauma could include injuries from hitting your head, like a concussion, or brain infections that can temporarily affect short-term memory. Amnesia can be caused by trauma to the brain, drug overdoses, and emotional shocks. These could result in permanent memory loss, although some have regained memories over time.
5. Alcohol or Drug Abuse
Drug or alcohol additions can affect your memory over time. If you are intoxicated, many times you cannot remember anything. This can be reversed with long-term sobriety.
4. Silent Strokes
Silent strokes are small and can go undetected. It can happen while you sleep or even when awake, but with no symptoms. This can still cause brain damage, which is often irreversible, but possible improvements can be seen over time.