Memory loss: other causes

See your GP first

The NHS advises that you should not try to work out the cause of memory loss yourself. Always see a GP.

NICE, which sets guidance for the NHS, asks GPs to look for causes of memory and thinking problems that can be treated before thinking about dementia. These include delirium, depression, problems with sight or hearing, and side effects of medicines. GPs also arrange blood and urine tests.

Finding one of these causes does not rule out dementia. Some people have more than one thing going on. But it is important to check.

Delirium

Delirium is a sudden change in how clearly someone can think. A person may:

• be unable to think or speak clearly
• not know where they are
• have trouble paying attention
• see or hear things that are not there
• be much sleepier than usual, or restless and agitated

The NHS lists common causes such as urinary tract infections (especially in older people), stroke or mini stroke, low blood sugar, head injury, some medicines and alcohol.

The key difference is speed. Dementia usually develops slowly over months or years. Delirium comes on over hours or days. People who already have dementia are more likely to develop delirium, so a sudden change in someone with dementia also needs urgent help.

While waiting for help, the NHS suggests staying with the person, reassuring them, using short simple sentences, and noting any medicines they take.

Mild cognitive impairment

Mild cognitive impairment (MCI) means having problems with memory or thinking that are noticeable but do not stop you managing most daily tasks.

Alzheimer’s Society explains that MCI is different from dementia. Dementia always gets worse over time. MCI can stay the same, improve, or in some people go on to become dementia. MCI can be caused by other health problems, such as sleep disorders or the side effects of medicines.

If you are told you have MCI, ask the GP or memory service about follow-up and what to look out for.

Depression and anxiety

The NHS lists stress, anxiety and depression as common causes of memory problems. When you are low or anxious, it can be hard to concentrate, take in new information and make decisions. You may feel your memory is failing when the real problem is that worry or low mood is using up your attention.

A note on “pseudodementia”

You may come across the word “pseudodementia”. It is an older term some people use when depression causes memory and thinking problems that look like dementia. It is not a formal diagnosis, and it can be misleading:

• depression and dementia can happen at the same time
• low mood can be an early symptom of dementia
• the NHS lists untreated depression as a risk factor for Alzheimer’s disease

So if you are low and worried about your memory, both need attention. The GP can treat depression and still refer you to a memory service if concerns remain.

In England, you can refer yourself to NHS Talking Therapies for anxiety and depression, if you are registered with a GP.

Thyroid problems

An underactive thyroid gland (hypothyroidism) can slow the body down. The NHS lists difficulty concentrating or thinking clearly, and low mood, among its symptoms. It is diagnosed with a simple blood test and is usually treated with daily tablets.

Vitamin B12 and folate

The NHS says a lack of vitamin B12 can cause problems with memory, understanding and judgement. It can also cause psychological problems ranging from mild depression or anxiety to confusion and dementia. The NHS warns that some problems can become permanent if it is not treated, so early testing matters.

Medicines

Some medicines can affect memory and thinking, especially in older people or when several are taken together. NICE asks doctors to be aware that some commonly prescribed medicines add to what is called “anticholinergic burden”, which can increase thinking problems, and to reduce these where possible.

Do not stop or change any medicine yourself. Ask your GP or pharmacist for a medicines review.

Alcohol

Drinking too much alcohol can affect memory. Long-term heavy drinking can cause alcohol-related brain damage (ARBD). Alzheimer’s Society says that with support to stop drinking, some people with ARBD make a partial or even full recovery. If you want to cut down, talk to your GP, especially if you drink heavily, as stopping suddenly can be dangerous.

Sleep problems

The NHS lists insomnia as a cause of memory problems. Poor sleep makes it harder to concentrate and remember. Sleep problems can be linked to worry, pain, needing the toilet at night, or conditions such as sleep apnoea. The NHS suggests regular sleep and wake times, and seeing a GP if problems last or affect daily life.

Hearing and sight

If you cannot hear or see clearly, it is harder to take in information, so you may not remember it. NICE lists sight and hearing loss as things to check.

Alzheimer’s Society also says hearing loss in mid-life is linked to a higher risk of dementia, and that hearing aids may help reduce thinking problems in people at risk. Have your hearing and eyes tested regularly.

Menopause

The NHS says menopause can cause problems with memory or concentration, sometimes called brain fog. These can feel worse with poor sleep and tiredness. Talk to your GP about symptoms and treatment options.

Other causes

Other causes a GP may consider include infections, head injuries, stroke, and other physical illnesses. This is why a check-up and blood tests are an important first step. See getting a diagnosis.

Quick guide to common causes

When mood affects memory

Sometimes, after the GP has checked for physical causes, low mood or anxiety seems to be a big part of the picture. Treating depression or anxiety can help concentration.

If your memory problems are getting worse, or you or others are worried about dementia, the GP and NHS memory service are the right route. Read about early signs, and see support and helplines for advice by phone.