You might think that some changes, like memory loss, are inevitable as the years roll by. And that can be true – but serious conditions like dementia, though more common among older people, are not an ordinary part of healthy ageing.

In general, Dominic Greenyer, a private GP at The Health Suite, told HuffPost UK: “Ageing naturally brings some change. People may notice a modest reduction in muscle mass, bone density, cardiovascular fitness, hearing, vision or the speed at which they process information.

“However, severe or rapidly progressing decline should not automatically be dismissed as an inevitable part of getting older.”

Sometimes, people call non-standard deterioration “pathological ageing”. Here, we asked the GP to explain what the term means, as well as the signs you may be experiencing one or the other.

It’s not a single formal condition, the doctor said.

Instead, pathological ageing describes “deterioration driven or accelerated by disease, rather than the gradual biological changes we would ordinarily expect as a person grows older… [it may] involve illness or damage that significantly affects a person’s function and independence”.

That might include cardiovascular disease, poorly controlled diabetes, osteoporosis, dementia, chronic lung disease, severe frailty or substantial muscle loss.

“One of the dangers of describing every new symptom as ‘just old age’ is that treatable conditions can be missed,” the GP continued.

“Persistent exhaustion, unexplained weight loss, repeated falls, worsening breathlessness, new confusion, significant memory changes or a sudden loss of strength should be properly assessed.”

Older people may be led to believe that “pain, fatigue or loss of mobility is something they simply have to tolerate”; but that’s not always the case.

“The important questions are how quickly the change has happened, whether it is affecting everyday life, and whether an underlying condition may be contributing to it.”

Dr Greenyer said that healthy ageing doesn’t mean reaching old age without any disease whatsoever. In fact, he considers healthy vs pathological ageing as more of a “spectrum” than separate poles.

“Many people live well with arthritis, high blood pressure or other long-term conditions when these are recognised, treated and properly controlled,” he said.

But a person’s level of functionality matters here.

“Healthy ageing means preserving as much physical capacity, cognitive ability, independence and social engagement as possible. A person may have a diagnosis but still remain active, make their own decisions, maintain relationships and continue doing the things that matter to them,” the GP explained.

“Pathological ageing is more likely to involve decline that is disproportionate, accelerated or driven by disease. It can begin to restrict mobility, memory, resilience and the ability to manage ordinary tasks.”

People can move between pathological and healthy ageing, he added. “Early diagnosis, rehabilitation, better disease control and changes to daily habits can sometimes slow decline and restore a meaningful amount of function.”

Dr Greenyer stressed that lifestyle changes alone can’t guarantee healthy ageing – genes and other factors outside our control can play a part here.

Therefore, he said, “people should never be blamed for illnesses that are not entirely within their control”.

With that said, some habits can make a “significant difference” to how likely we are to age well.

Not smoking “remains one of the most important steps a person can take,” the GP stated, while controlling and monitoring blood pressure, cholesterol and blood sugar can go a long way too.

“Good-quality sleep, meaningful social contact and continuing to challenge the brain are also important,” he said, while depression and hearing loss are often “overlooked” factors that can make ageing well less likely.

Calling regular physical activity “one of the most powerful things we can do.” Dr Grenyer stated that “Aerobic activity supports the heart, lungs and circulation, while strength training helps preserve muscle, bone density, balance and the ability to perform everyday tasks”.

You don’t need to hit the gym every day, either. Brisk walking, cycling, swimming, gardening, carrying shopping and simple resistance exercises can all help, the expert advised, while balance work is great for better ageing (especially among those prone to falls).

Diet is important, as well – “Older adults need sufficient protein to help preserve muscle, alongside vegetables, fruit, wholegrains and sources of healthy fats. People should also pay attention to hydration, as the sensation of thirst can become less reliable with age”.

Lastly, the GP told us that prevention isn’t just about lifestyle choices. Getting vaccines, attending screenings, and seeing your doctor about new concerns matters, too.

“The goal is not to stop ageing, because that is impossible. It is to protect resilience, function and independence for as long as possible, while recognising that it is never too late to make changes that may improve health and quality of life.”