If you're concerned about memory problems, do consult your GP as soon as possible. But it's also worth bearing in mind that more than half of patients referred to memory clinics for confirmation of a dementia diagnosis turn out not to have the condition, according to recent figures from the University of Sheffield. So what else could be causing the issue?
It's the menopause
Sixty per cent of menopausal women experience memory problems due to fluctuating hormone levels, according to a University of California study (http://www.ncbi.nlm.nih.gov/pubmed/19470968). And these difficulties tend to be most evident in the year immediately following a woman's final period, say researchers at the University of Rochester.
The good news, though, is that the effect is temporary: memory skills tend to return to pre-menopausal levels in the years after the menopause. 'The most important thing that women need to be reassured of is that these problems, while frustrating, are normal and, in all likelihood, temporary,' says Dr Miriam Weber, who led the Rochester study.
Related: Post-menopause positives
You've been under a lot of stress
Long-term stress can lead to brain structure changes that may erode short-term memory skills, says a study at The Ohio State University. Mice who had been repeatedly exposed to stress – in the form of bullying by a bigger mouse – were unable to locate the escape hole in a maze they'd previously mastered. Mice who hadn't been bullied managed to find the exit without a problem.
The stressed mice also experienced measurable brain changes, including inflammation caused by the immune system's response to the outside pressure. You'll be pleased to hear they'd made a full recovery within 28 days, though.
Related: Stress – what it does to your health
Need another good reason to lose a few pounds? Being overweight is associated with poor episodic memory, says a recent University of Cambridge study. Fifty adults of varying sizes were asked to complete a test that involved hiding items around a complex environment over two days and later recalling when and where they'd hidden them. People with a high body mass index (BMI) tended to fare significantly worse.
The researchers' conclusion? 'Although only a small study, its results support existing findings that excess body weight may be associated with changes to the structure and function of the brain and its ability to perform certain cognitive tasks optimally.'
Related: Do you need to lose weight?
You had a bad night
Just one restless night can have a dramatic effect on your memory skills, according to a US study. Participants were shown images of a simulated burglary, then asked to recall the details the following day. Those who'd been kept awake for 24 hours – and even those who'd had up to five hours of sleep – were more likely to mix up the information.
'People who repeatedly get low amounts of sleep every night could be more prone in the long run to develop these forms of memory distortion,' says the study's co-author Dr Kimberly Fenn. 'It's not just a full night of sleep deprivation that puts them at risk.'
Related: 10 healthy reasons to get a better night’s sleep
You're getting too much sleep
Yes, there is such a thing! Women who slept for nine hours or more on average performed just as badly in cognitive tests as those who slept for less than five hours, in a recent Harvard study. Researchers estimated that both 'under-sleepers' and 'over-sleepers' were mentally two years older than those who enjoyed seven to eight hours of slumber each night.
Your diet's to blame
Foods laden with sugar and fat appear to reduce levels of a natural brain chemical, called BDNF, which is crucial for learning and memory skills, say researchers at the University of California.
Meanwhile, a diet rich in omega-3 fatty acids – found in oily fish and walnuts, for example – is associated with many brain-boosting benefits.
But it's not just what you eat that impacts your memory; when you eat it makes a difference, too. Regularly indulging in late-night snacks, which means your body is busy digesting food while you're asleep, can damage the hippocampus – the part of the brain where memories are formed – according to another recent US study.
Related: Sources of omega-3 for people who don’t like salmon
Can't remember where you left your keys? Try drinking a glass of water. Even very mild dehydration can alter our ability to think clearly and remember simple things, say researchers at the University of Connecticut.
The feeling of thirst doesn't really kick in until we're already one or two per cent dehydrated – and that can be enough to impair our powers of recall.
Related: Strategies to prevent dehydration