Rates of dementia and heart failure in Jersey are projected to rise by around 50% over the next twenty years.
Projections suggestion cases of the diseases will increase by 52% and 42% respectively by 2043.
That represents and additional 1,250 with dementia and 1,680 people with heart failure.
A report by Public Health looks at the strain the ageing population will put on our health services, and estimates we will need 10% more GPs to cope.
Demand for doctor appointments could rise by 36,000 a year, while days spent in hospital will be up by almost a third.
Dementia Jersey CEO Claudine Snape says the report confirms rising rates of what is already the island's leading single cause of death.
"This, together with our ageing population, means it’s the right time to put the needs of people with dementia at the top of the agenda.
We have to make it a priority now, in terms of how we care for people and how we improve our services to meet the needs of those people and their carers.
By co-authoring the Dementia Strategy for Jersey we’ve been given a unique opportunity to achieve a step change for people with dementia and their families."
The island's first dementia strategy is expected to be made public soon.
People are reminded that these are projected figures, and that with the right lifestyle changes, some can be avoided.
Dementia Jersey says stopping smoking, exercising more and improving heart health can help curb 40% of diagnoses.
Separate data - published this week - suggests the number of people living with more than one long term health condition is forecast to rise by a fifth by 2043.
Already more than 14,000 islanders are living with multi-morbidity.
It's more common in older generations, with people aged 85 and over the most likely to suffer from multiple conditions.
Figures from GP records reveal hypertension is the most common illness, affecting 17% of the population.
The most commonly co-occurring conditions are high blood pressure, diabetes and obesity.