Long-term memory is how your brain stores information over time. It includes remembering events, facts, and how to complete tasks, like how to find your way home.

Long-term memory loss is when you have trouble recalling this information when you need it. Many people’s long-term memory starts to get weaker as they get older. This is a normal part of aging.

Existing between normal age-related memory changes and dementia is the condition known as mild cognitive impairment (MCI). In 2013, it was estimated that 16 to 20 percent of adults over 60 had some form of MCI, which is impairment not severe enough to be classified as dementia.

But long-term memory loss can also be a sign of a more serious problem, such as dementia.

Approximately 10 percent of Americans ages 65 and older have Alzheimer’s disease, which accounts for most cases of dementia. Long-term memory loss can also be a sign of other health conditions and diseases.

The main symptom of long-term memory loss is forgetting things that happened earlier in your life, which may have had some importance or significance for you, such as the name of your high school or where you lived.

Other symptoms include:

  • mixing up words, such as calling a table a bed
  • forgetting common words
  • getting lost in familiar places
  • taking longer to do familiar tasks
  • mood and behavior changes, such as increased irritability

There are a variety of causes of memory loss, some of which may be reversible. In most of these causes, you can treat memory loss by treating the underlying cause.

Reversible causes of long-term memory loss include:

Other causes of long-term memory loss may be the result of damage to the brain. Generally not completely reversible, some symptoms may improve depending on how bad the damage is and what parts of the brain are affected.

These causes of long-term memory loss include:

  • drug and alcohol misuse
  • serious brain injuries, such as concussions
  • severe brain infections
  • brain tumors
  • strokes
  • oxygen loss
  • epilepsy, specifically severe seizures

Some causes of long-term memory loss aren’t reversible, such as dementias, including Alzheimer’s disease.

Dementia can cause both short and long-term memory loss, especially in older adults.

Dementia is a general term for cognitive decline that interferes with daily living. It’s progressive, which means it gets worse over time.

While there’s no cure for dementia, there are medications that can help reduce symptoms.

Different types of dementia include:

Alzheimer’s disease

Alzheimer’s disease causes the progressive impairment of memory, comprehension, language, reasoning, judgment, and attention.

It accounts for two-thirds of dementia cases in people 65 and older and is the 6th leading cause of death in the United States.

Short-term memory loss is the most common first symptom. After that, memory loss — including long-term memory loss — increases and other symptoms start to appear.

Lewy body dementia

Lewy body dementia is caused by abnormal deposits of a protein called alpha-synuclein in the brain. These deposits affect brain chemistry, which affects movement, thinking, and behavior.

It usually starts around age 50 or older, and is slightly more common in men.

Lewy body dementia does cause memory problems in later stages, but movement problems are usually the first symptom.

Frontotemporal dementia

Frontotemporal lobe dementia (FTD) is more likely to be diagnosed in younger people than other forms of dementia. Personality and mood changes are usually the first symptoms, followed by language issues and memory loss.

Vascular dementia

Vascular dementia is caused by stroke and other vascular brain injuries. It has the same risk factors as cardiovascular problems, such as high blood pressure.

Symptoms of vascular dementia are very similar to Alzheimer’s disease. It also causes progressive loss of memory and other cognitive functions, including organization, attention, and problem solving.

While memory loss is a common symptom of dementia, not all long-term memory loss means that you have dementia. Your doctor can help you figure out the underlying cause.

To diagnose long-term memory loss, your doctor will first take a medical history. They’ll ask about your family history, any medications you take, and any other health problems.

They’ll also ask questions about your memory loss, such as:

  • how long it’s been going on
  • how your memory has been affected
  • what your other symptoms are
  • if your symptoms have been getting worse over time

Your doctor will then do a physical exam to see if you have symptoms like muscle weakness that can help them make a diagnosis.

They will probably also conduct blood tests to check for vitamin deficiencies and perform neuroimaging tests such as an MRI or CT scan to see if there are any physical issues with your brain.

Your doctor may ask you questions about current or past events — basic tests which require you to remember information or perform basic math calculations. You may also be asked to:

  • repeat certain phrases
  • read and write short sentences
  • name common objects

Sometimes, you’ll be referred to a psychologist who can conduct comprehensive neuropsychological testing to learn the extent of your memory loss and cognitive impairment.

In many cases, your medical history, symptoms, and neurocognitive tests will be enough for a doctor to make a diagnosis.

Depending on the diagnosis, your doctor might then send you to other specialists — such as a geriatrician, neurologist, or psychiatrist to help with the medical management of your disorder.

A referral to a psychologist or other licensed counselor may be done to help you cope with your memory loss.

Treatment for long-term memory loss depends on the underlying cause.

For example, if your memory loss is caused by a medication, your doctor will switch you to another one. If your memory loss is caused by a treatable illness, your doctor can treat that illness.

Some causes of long-term memory loss might require surgery. For example, you might have a brain tumor removed with surgery, or have a structural abnormality of the brain that requires correction.

There’s no cure for Alzheimer’s disease, but there are medications that can help reduce your symptoms.

Cholinesterase inhibitors and partial N-methyl D-aspartate (NMDA) antagonists are the two classes of medication approved to treat Alzheimer’s disease. Two types of cholinesterase inhibitors can be used for mild to moderate Alzheimer’s, while another type can be used at any stage. NMDA antagonists are generally used in later stages.

These drugs can be beneficial for some people, but not for everyone, and side effects have to be weighed against benefits.

There are also things you can do at home to help memory loss. Regular exercise, a healthy diet, learning new things, and a healthy sleep schedule have all been shown to help reduce memory loss.

Some short- and long-term memory loss is a normal part of aging. But if your memory loss starts to interfere with your daily life, you should see a doctor.

You should also see a doctor if:

  • you recently had a head injury
  • you have other symptoms of physical or mental illness
  • you’re also disoriented or confused

If you have other serious symptoms, such as delirium or a head injury, long-term memory loss might be a medical emergency. See a doctor immediately.

Long-term memory loss can seem scary, but minor memory loss can be a normal part of aging for many people.

If your memory loss interferes with daily life, see your doctor. Many causes of memory loss may be treatable.