Dementia is not a natural part of ageing, the Alzheimer's Society made clear, but there are times when your risk of developing the condition is heightened.
"A person who is aged over 75 is more likely to develop dementia than someone who is under 75," the charity says.
For people aged between 65 to 69, around two in 100 people will have dementia.
A person's risk of dementia roughly doubles every five years in older age, after 69.
In those aged over 90, around 33 in every 100 people will have dementia.
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The charity adds: "The longer a person lives, the more time there is for dementia to develop."
Ageing is a risk factor for dementia because there is an increased likelihood of having other conditions that contribute to the development of dementia.
Examples include high blood pressure and a weakened immune system.
Aside from older age, there are other factors that contribute to the development of dementia.
There is a familial dementia gene that can be passed down from parent to child.
Thus, if a parent has a familial gene for dementia, and they develop dementia, their child has a 50 percent chance of developing the condition too.
"These genes may be the cause of around one in three cases of frontotemporal dementia," the charity points out.
There are also 20 "risk genes" for dementia, but they "only slightly increase a person's risk of dementia".
The Alzheimer's Society elaborates: "The most important risk gene for dementia is called apolipoprotein E (APOE).
"Certain versions (variants) of the APOE gene can make a person up to four times more likely to develop Alzheimer's disease than people who don't have this version of the gene."
One of the best ways to minimise your risk of developing dementia is to connect to people socially, keep the brain active, and lead a healthy lifestyle.
If you are concerned you might be developing dementia, do book a doctor's appointment.