There will be a 59% rise in the number of people suffering a stroke over the next 20 years, a new report suggests.
High blood pressure, which is linked to unhealthy lifestyles, and the fact people are living longer is helping fuel a rise in strokes, the Stroke Association study found.
It said first-time strokes among people aged 45 and over in the UK will rise from 117,600 in 2015 to 148,700 in 2025 and 187,000 in 2035, a 59% rise over 20 years.
The main rise is expected to be among people aged 85 and over. At the same time, more people aged 45 and over will survive a stroke, although around a third will be left disabled.
Stroke survivors in the UK will rise from 950,000 in 2015 to 1,425,000 in 2025 and 2,120,000 in 2035, a 123% rise over 20 years.
Around 700,000 of these will be left with long-term disabilities.
The report also found the yearly cost of stroke to the NHS will also treble, from £3.4 billion in 2015 to £10.2 billion in 2035.
But the charity says investing £10 million in research to prevent strokes could save 114,000 people from having a stroke by 2035.
Dominic Brand, director of external affairs at the Stroke Association, said: "It's clear that we need to act now to prevent the UK from sleepwalking towards a stroke crisis."
He added: "The fact is that most strokes are preventable but there's still a lot we don't know.
"This report highlights some of the key areas that desperately need investment.
"We are currently funding a number of smaller studies focusing on stroke prevention, including blood pressure management, treatments for atrial fibrillation (AF), and the prevention of haemorrhagic stroke."
AF, also known as irregular heartbeat, can increase a person's risk of stroke five-fold.
The report said many sufferers are on inadequate treatment and an estimated 250,000 people are living with undiagnosed AF.
Around five million people are also undiagnosed with high blood pressure, the biggest controllable risk factor for stroke.