Building the brain…

A visual explainer

How Alzheimer's
changes the brain

Travel from the whole brain down to a single nerve cell, and back out again, to see how the disease unfolds.

Around 982,000 people in the UK live with dementia, and Alzheimer’s disease causes roughly six in ten of those cases. One in three people born today will develop dementia in their lifetime.

01 · A healthy brain

Billions of cells, constantly talking.

Nerve cells, or neurons, pass messages to each other as tiny electrical and chemical signals. Every thought, memory and movement depends on these connections.

02 · Plaques

Amyloid proteins build up around brain cells.

Fragments of a protein called amyloid collect in the spaces between neurons. Gradually they stick together into clumps known as plaques.

03 · Tangles

Tau proteins form tangles inside brain cells.

Inside a neuron, tau normally helps hold its internal transport tracks together. In Alzheimer's, tau changes shape, comes away from the tracks and twists into tangles.

Plaques and tangles develop alongside each other, over many years.

04 · Communication

Brain cells become damaged and struggle to communicate.

Signals grow weaker and less frequent. One by one, the connections between cells are lost.

Plaques and tangles do not always mean dementia. Some people have them and never develop symptoms.

“I’d forget the simplest of words, or the names of people I’d worked with forever.”

Wendy Mitchell, diagnosed with young-onset Alzheimer’s at 58, speaking to Age UK

05 · Cell loss

Over time, brain cells die and parts of the brain shrink.

As neurons are lost, the affected regions of the brain gradually shrink. Areas involved in memory are often affected first.

06 · Everyday life

Memory, thinking and everyday tasks become harder.

A recent conversation slips away. A familiar routine becomes confusing. Words that were always there are suddenly out of reach.

“I’m Andy’s carer now – but I’m also still his partner.”

Christine, whose partner Andy has young-onset dementia, speaking to Dementia UK

These changes build up over many years, and what first sets them in motion is still not fully understood.

07 · What can be done

Research is starting to change the picture.

New treatments can clear amyloid from the brain and modestly slow early decline. Blood tests are making diagnosis earlier and simpler. Neither is a cure, and neither suits everyone.

“I like to think of a diagnosis as the beginning of a different life.”

Wendy Mitchell, dementia campaigner and author, speaking to Age UK

Some of what raises the risk can be changed. Hearing loss, high blood pressure, smoking, inactivity and isolation all play a part.

Source: NHS