What are the causes of memory loss?
Memory loss has many possible causes that differ greatly from one another. If you suddenly develop memory problems, always have them assessed by a doctor so that a treatable cause is not missed.
Memory loss has many different causes, depending on which part of the brain is affected and how quickly the symptoms come on. The best-known cause is damage to the hippocampus, the brain region that stores personal memories. This occurs in Alzheimer's disease, but also in brain injury caused by an accident or a blow to the head. People who sustain damage to the frontal lobe may struggle to actively hold on to information, or may unconsciously begin to fabricate memories.
Acute memory loss that comes on suddenly has different causes. The most common is an episode in which a person is temporarily unable to form new memories, which resolves on its own within 24 hours. This is fully reversible and rarely looks dangerous. A stroke can also cause sudden memory loss, but in that case it is sometimes permanent. Epileptic seizures in the memory circuits of the brain produce brief, episodic moments of forgetting that can be distinguished from that transient episode.
Alcohol and certain medications or drugs represent another category: they disrupt memory acutely, without causing structural brain damage. A severe deficiency of vitamin B1, such as in long-term alcohol misuse, can lead to Korsakoff psychosis: a serious and often permanent memory disorder. Oxygen deprivation in the brain, for example after resuscitation, damages memory structures and can have comparable consequences.
Sometimes the cause lies not in the brain itself but in the immune system or an infection. If the immune system attacks brain tissue, or following meningitis, memory loss can occur as a complication. Psychiatric causes are also possible: in dissociative amnesia there is no demonstrable structural brain damage, but information appears not to be properly encoded at the point of input.
Finally, there is mild cognitive impairment, an intermediate stage between normal aging and dementia. People with this condition have measurable memory problems but are still able to manage independently. Not everyone with these complaints goes on to develop dementia, but it does increase the risk. Surgery and anaesthesia can cause temporary memory loss; this is well recognised, but the precise cause is not yet fully understood.
This answer is based on multiple review studies by neurologists and memory specialists who systematically map the causes of memory loss. The evidence for structural causes such as hippocampal damage and strokes is solid; for less common causes such as post-infectious amnesia and postoperative memory loss it is thinner and less well understood.
How do you train your memory effectively?
Memory can be trained, but the smartest investment is regular exercise: that has the strongest and broadest support for cognition and memory. Targeted memory training helps, but less spectacularly than is often assumed.
What is the link between gum disease and heart disease?
There is a consistent association between gum disease and a higher risk of heart disease, although it has not been proven that one causes the other. Taking good care of your gums is sensible regardless, but do not expect any guaranteed protection against heart disease from doing so.
Is eating 800 grams of fruits and vegetables per day healthier than the standard guideline?
More than 400 grams per day helps, but whether 800 grams is clearly healthier than 400 grams depends on your goal: for cardiovascular disease there is evidence that the curve continues toward 800 grams, while for life expectancy and cancer the benefit above five portions is less convincingly demonstrated.
Does hearing loss increase your risk of dementia, and does a hearing aid help?
Hearing loss demonstrably increases the risk of dementia, and a hearing aid appears to help, but proven protection for everyone has not yet been established. Have hearing loss assessed in any case, if only because of the other health risks associated with it.
Does poor sleep cause dementia sooner?
Poor sleep probably increases your risk of dementia, but ordinary insomnia does not make dementia inevitable. One exception: if you physically act out your dreams while sleeping, discuss that with a doctor.