Risk factors
Alzheimer's disease
In this section:
What causes Alzheimer's disease?
A risk factor is something that affects our chances of developing a condition like dementia. Most cases of dementia are caused by a mixture of risk factors including our:
Some of these things we cannot influence, like our age and our genes. Age is the biggest risk factor for developing Alzheimer’s. The older you are, the more likely you are to develop it.
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Risk factors we may be able to influence
There is no surefire way to prevent dementia. This means that many people live a healthy and active life and still develop it.
However, research suggests almost half of dementia cases worldwide could be prevented or delayed by addressing health and lifestyle factors.
Maintaining a healthy lifestyle in your forties and fifties seems to be particularly important for helping to reduce your dementia risk. But taking steps to look after our health is important at any age.
By keeping your brain and heart healthy, you will be lowering your risk of Alzheimer’s or delaying its onset.
For good brain health, and to help lower your risk of Alzheimer’s disease:
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Keep physically active.
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Stay socially and mentally active
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Don’t smoke.
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Eat a healthy balanced diet.
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Keep cholesterol and blood pressure under control.
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Maintain a healthy weight.
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Have your hearing and eyesight checked regularly.
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If you have Type 2 diabetes, ensure your condition is well managed.
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Only drink alcohol within the recommended limits
Is Alzheimer's disease inherited?
There are around 600,000 people living with Alzheimer’s in the UK, so many of us are likely to have at least one relative with the disease. But this doesn’t mean that we will inherit it.
Risk genes
If someone has a parent or grandparent with Alzheimer’s who developed the disease after the age of 65, then their own risk of developing Alzheimer’s may be slightly higher than someone with no family history. This is because they are more likely to have risk genes.
People who inherit risk genes from one or both parents are more likely to develop Alzheimer’s. But having these risk genes does not mean someone will definitely develop the disease. This is because there are still steps we can all take to look after our brain health.
There is currently no genetic testing available on the NHS to find out if we carry risk genes or not.
Faulty genes
In rare cases, young onset Alzheimer’s can run in families. Young onset dementia is where symptoms begin before the age of 65.
When young onset Alzheimer’s runs in families, the disease is caused by faulty genes. People who inherit these genes are very likely to develop Alzheimer’s during their lifetime.
In these families, many people on the same side of the family are affected, often in their 30s, 40s or 50s.
Around one in 100 cases of dementia are caused by these inherited faulty genes.
There are genetic tests available on the NHS to investigate these cases of Alzheimer's disease. If you are worried these cases are present in your family, you should talk to your GP.
People with Down syndrome are more likely to develop Alzheimer’s. They are also more likely to develop the disease at an earlier age. This is because the genetic differences in people with Down syndrome cause the faulty proteins amyloid and tau to build-up in the brain.
Mild cognitive impairment
Some people develop mild memory problems that are worse than expected for their age, but do not get in the way of normal daily life.
This is called mild cognitive impairment (MCI). While people with MCI are at an increased risk of developing Alzheimer’s, many people do not go on to develop the disease.
Some people with MCI may even regain normal memory function, depending on what is causing their symptoms.
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Dementia information
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This information was updated in May 2026 and is due for review in May 2028. It was written by Alzheimer's Research UK's Information Services team with input from lay and expert reviewers. Please get in touch if you'd like a referenced copy.
This information is produced with support from The Perfume Shop who had no input into the content.
