It’s normal to become a bit forgetful as you get older. However, memory loss could be a symptom of something more serious and should be checked by a doctor.
Memory loss, also called amnesia, occurs when a person loses the ability to remember events and information they would normally be able to recall. This could be something that happened only seconds or minutes ago, or a memorable event that happened in the past. The memory loss may have started suddenly or may have been getting worse over the last year or so.
Memory loss can be distressing, for the person affected as well as for their family. Relatives may fear the worst and assume it's caused by dementia, but this often isn't the case.
The following information will tell you:
- what to do if you're worried about memory loss
- how to tell if it could be caused by dementia
- the most common causes of memory loss (but don't rely on this to self-diagnose a condition)
- how to cope with a poor memory
What to do if you're worried about memory loss
If you're worried because you or someone you care for has lost their memory, see your doctor. They'll do an initial assessment and ask questions about symptoms, family history and lifestyle. They may also order a blood test.
Memory loss has a wide range of possible causes, depending on the type of memory loss.
Doctors classify memories as either:
- Immediate memories, such as sounds, which are only stored for a few seconds.
- Short-term or recent memories, such as telephone numbers, which stay in your memory for 15-20 seconds. The brain can store about seven chunks of short-term information at any time.
- Long-term or remote memories - more permanent memories, which have been reinforced because you've repeatedly gone over them in your mind.
If your doctor thinks that you or your relative needs an assessment for dementia or that there may be another more serious underlying condition, such as brain damage, they'll refer you to a specialist.
Could it be dementia?
If you're reading this because you think your memory problems may be a sign of dementia, rest assured that they probably aren't. A person with dementia will not usually be aware of their memory loss or may deny it.
Your memory loss is likely to be caused by something a lot more common and treatable, such as depression (see below).
You may be worried that someone you care for has dementia. However, bear in mind that around 40% of people aged over 65 have some kind of memory difficulty, and only 15% will develop dementia each year.
If your instincts are correct, their denial or lack of awareness of their memory loss can make it hard to convince them to see a doctor. It may help to read this fact sheet that includes information on how to persuade your relative to see a doctor (PDF, 849Kb).
Signs that someone has dementia
As a general guide:
- Dementia usually occurs in people over the age of 65.
- Someone with dementia will struggle to remember immediate or recent events, but can still recall events that happened a long time ago. Therefore, if their long-term memory is affected, it probably isn't dementia.
- The memory loss doesn't happen suddenly but gets gradually worse over time.
Find out more about the symptoms of dementia.
Common causes of memory loss
Generally, doctors find that patients who see them about memory loss are most likely to have:
Their memory loss is due to poor concentration and not noticing things in the first place because of a lack of interest. Sleeping problems make the memory loss worse.
Your doctor may suggest trying antidepressant tablets. If their assumption is correct, these should improve the memory problems as the depression lifts.
An elderly person with memory loss is likely to have depression if they also experience changes in behaviour, such as hoarding or being bad tempered.
Other common causes of memory loss are:
- a head injury, for example after a car accident
- a stroke that cuts off some of the blood supply to the brain and causes brain tissue to die
These will cause sudden memory loss, where you either forget events that happened before the trauma (retrograde amnesia), or you forget everything that happened after the trauma (anterograde amnesia).
Less common causes of memory loss
Less commonly, memory loss can be caused by:
- an underactive thyroid, which means your thyroid gland (found in the neck) does not produce enough hormones
- certain types of medication, such as sedatives and some [treatments for Parkinson’s disease]
- long-term alcohol misuse
- bleeding in the brain, known as subarachnoid haemorrhage
- vitamin B1 (thiamine) deficiency, for example because of a digestive problem
- problems with blood flow to part of the brain, which cause sudden episodes of memory loss that a person cannot recall afterwards (known as transient global amnesia]
- a stressful or traumatic event that causes someone to block out the memory, leaving them unable to remember important information (known as psychogenic amnesia)
- a brain tumour
Click on the links above for more information on these conditions.