Memory loss, also referred to as amnesia, is an abnormal degree of forgetfulness and/or inability to recall past events. Depending on the cause, memory loss may have either a sudden or gradual onset, and memory loss may be permanent or temporary. Memory loss may be limited to the inability to recall recent events, events from the distant past, or a combination of both. Although the normal aging process can result in difficulty in learning and retaining new material, normal aging itself is not a cause of significant memory loss unless there is accompanying disease that is responsible for the memory loss.
Transient global amnesia is a rare, temporary, complete loss of all memory. Anterograde amnesia refers to the inability to remember recent events in the aftermath of a trauma, but recollection of events in the distant past in unaltered. Retrograde amnesia is the inability to remember events preceding a trauma, but recall of events afterward is possible.
Memory loss has multiple causes including a number of chronic medical and psychological conditions, trauma, medications, drug or alcohol abuse, and infections.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.
Pictures, Images, Illustrations & Quizzes
Alzheimer's Diagnosis: Your Family's Questions Answered
Is there any difference between Alzheimer's disease and Dementia? Is Alzheimer's disease deadly? Find out the truth about...
Alzheimer's Disease Symptoms & Early Diagnosis
Learn the early warning signs and symptoms of Alzheimer's disease. Memory loss and confusion can be signs of normal aging, but...
Alzheimers Disease Quiz: Stages, Symptoms & Signs
Take the Alzheimer's Quiz to discover some of the mysteries behind this cognitive disorder. Learn causes, symptoms, treatments,...
Caring for Someone With Alzheimer's Disease
Use this guide for advice on caring for someone with Alzheimer's. Learn to spot early signs and symptoms of Alzheimer's disease...
Dementia, Alzheimer's Disease, and Aging Brains
What is dementia? Learn about dementia disorders such as Lewy Body Dementia, Alzheimer's disease (AD), Vascular (multi-infarct)...
Picture of Alzheimer's Disease
In the early stages of Alzheimer's disease, patients may experience memory impairment, lapses of judgment, and subtle changes in...
Picture of Multiple Sclerosis Symptoms
Symptoms of multiple sclerosis may be single or multiple and may range from mild to severe in intensity and short to long in...
Causes of Memory Loss
Alcohol and Teens
Alcohol is the most frequently used drug by American teenagers. Teens that drink are more likely to drive under the influence,...
Alcoholism is a disease that includes alcohol craving and continued drinking despite repeated alcohol-related problems, such as...
Alzheimer's disease is a common cause of dementia. Symptoms and warning signs of Alzheimer's disease include memory loss,...
Brain Damage: Symptoms, Causes, Treatment
Brain damage causes destruction or deterioration of brain cells. Traumatic brain injury (TBI) and acquired brain injury (ABI) are...
Brain Tumor (Symptoms, Signs, Types, Causes, Survival Rates)
A brain tumor can be either non-cancerous (benign) or cancerous (malignant), primary, or secondary. Common symptoms of a primary...
Chronic Fatigue Syndrome (CFS or SEID)
Chronic fatigue syndrome (CFS) or systemic exertion intolerance disease (SEID) is a debilitating and complex disorder...
Creutzfeldt-Jakob disease (CJD) is a rare, degenerative, invariably fatal brain disorder. CJD generally appears in the later...
Dementia is defined as a significant loss of intellectual abilities such as memory capacity, severe enough to interfere with...
Depression is an illness that involves the body, mood, and thoughts and affects the way a person eats and sleeps, the way one...
Drug addiction is a chronic disease that causes drug-seeking behavior and drug use despite negative consequences to the user and...
Encephalitis is a brain inflammation that causes sudden fever, vomiting, headache, light sensitivity, stiff neck and back,...
Encephalopathy means brain disease, damage, or malfunction. Causes of encephalopathy are varied and numerous. The main symptom of...
Fibromyalgia is a chronic pain condition characterized by symptoms such as fatigue, sleep disturbances, and tender points. Stress...
Human Immunodeficiency Virus (HIV)
The human immunodeficiency virus (HIV) causes HIV infection and the acquired immunodeficiency syndrome (AIDS). Symptoms and signs...
Hydrocephalus is an abnormal buildup of cerebrospinal fluid (CSF) in the ventricles of the brain. The fluid is often under...
Jet lag (desynchonosis) is a temporary disorder that results from travel across time zones. Symptoms include anxiety,...
Lewy Body Dementia (Dementia with Lewy Bodies)
Lewy body dementia (LBD or dementia with Lewy bodies) is one the most common causes of dementia. There are two types of LBD: 1)...
Multiple Sclerosis (MS) Symptoms, Causes, Treatment, Life Expectancy
Multiple sclerosis or MS is an autoimmune disorder in which brain and spinal cord nerve cells become demyelinated. This damage...
Parkinson's disease is a slowly progressive neurological disease characterized by a fixed inexpressive face, a tremor at rest,...
Frontotemporal dementia (FTD) is a syndrome that is associated with shrinking of the frontal and temporal lobes of the brain....
Epilepsy is a brain disorder in which the person has seizures. There are two kinds of seizures, focal and generalized. There are...
Stroke (Signs, Symptoms, Warning Signs)
A stroke is an interruption of the blood supply to part of the brain caused by either a blood clot (ischemic) or bleeding...
Teen Drug Abuse
Drugs commonly abused by teens include tobacco products, marijuana, cold medications, inhalants, depressants, stimulants,...
There are several types of thyroid disorders including hypothyroidism, hyperthyroidism, goiters, thyroid nodules, and thyroid...
Transient Ischemic Attack (TIA, Mini-Stroke)
When a portion of the brain loses blood supply, through a blood clot or embolus, a transient ischemic attack (TIA, mini-stroke)...
West Nile Virus
West Nile virus (West Nile encephalitis) is a brain infection caused by a virus. People become infected with the virus after...
Other Causes of Memory Loss
Examples of Medications for Memory Loss
Subscribe to MedicineNet's General Health Newsletter