Memory loss


Memory loss (amnesia) is unusual forgetfulness. You may not be able to remember new events, recall one or more memories of the past, or both.

Alternative Names

Forgetfulness; Amnesia; Impaired memory; Loss of memory; Amnestic syndrome


Normal aging may cause some forgetfullness. It's normal to have some trouble learning new material, or needing more time to remember it.

However, normal aging does NOT lead to dramatic memory loss. Such memory loss is due to other diseases. Sometimes, memory loss may be seen with depression. It can be hard to tell the difference between memory loss and confusion due to depression.

Some types of memory loss may cause you to forget recent or new events, past or remote events, or both. You may forget memories from a single event, or all events. 

Memory loss may cause you to have trouble learning new information or forming new memories.

The memory loss may be temporary (transient), or permanent.

Common Causes

Memory loss can be caused by many different things. To determine a cause, your doctor or nurse will ask if the problem came on suddenly or slowly.

Many areas of the brain help you create and retrieve memories. A problem in any of these areas can lead to memory loss.

Causes of memory loss include:

  • Alcohol or use of illicit drugs
  • Not enough oxygen to the brain (heart stopped, stopped breathing, complications from anesthesia)
  • Brain growths (caused by tumors or infection)
  • Brain infections such as Lyme disease , syphilis, or HIV/AIDS
  • , such as surgery to treat seizure disordersBrain surgery
  • Cancer treatments, such as brain radiation, bone marrow transplant, or after chemotherapy
  • Certain medications
  • Certain types of seizures
  • Dementia
  • Depression, bipolar disorder, or schizophrenia when symptoms have not been well controlled
  • Dissociative disorder (not being able to remember a major, traumatic event; the memory loss may be short-term or long-term)
  • Drugs such as barbiturates or benzodiazepines
  • Electroconvulsive therapy (especially if it is long-term)
  • of any type (infection, autoimmune disease, chemical/drug induced)Encephalitis
  • that is not well controlled with medicationsEpilepsy
  • or injuryHead trauma
  • Heart bypass surgery
  • Illness that results in the loss of, or damage to, nerve cells (neurodegenerative illness), such as Parkinson's disease , Huntington's disease , or multiple sclerosis
  • Long-term alcohol abuse
  • Migraine headache
  • Mild head injury or concussion
  • Nutritional problems (vitamin deficiencies such as low vitamin B12 )
  • Permanent damage or injuries to the brain
  • Transient global amnesia
  • Transient ischemic attack (TIA)

Home Care

A person with memory loss needs a lot of support. It helps to show them familiar objects, music, or photos.

Write down when the person should take any medication or complete any other important tasks. It is important to write it down.

If a person needs help with everyday tasks, or safety or nutrition is a concern, you may want to consider extended care facilities, such as a nursing home.

What to expect at your health care provider's office

The doctor or nurse will perform a physical exam and ask questions about the person's medical history and symptoms. This will almost always include asking questions of family members and friends. They should come to the appointment.

Medical history questions may include:

  • Type
  • Time pattern
  • Aggravating or triggering factors
  • Other symptoms

Tests that may be done include:


Cognitive therapy, usually through a speech/language therapist, may be helpful for mild to moderate memory loss.

See: Dementia - homecare for information about taking care of a loved one with dementia.


Kirshner HS. Approaches to intellectual and memory impairments. In: Gradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. . 5th ed. Philadelphia, Pa: Butterworth-Heinemann; 2008:chap 6.

Encyclopedia content is provided as information only and not intended to replace the advice and instruction from your personal physician.