Alzheimer's Disease Explained

If a diagnosis has come back as Alzheimer's disease specifically, rather than dementia in general, it helps to understand what's actually happening, and what, realistically, can be done about it.

What's actually happening in the brain

Alzheimer's disease is caused by two abnormal protein processes. Amyloid plaques build up between brain cells, and tau tangles build up inside them. Together, these gradually damage the connections that let brain cells communicate with each other, and eventually cause those cells to die. This tends to start in areas of the brain involved in forming new memories, which is why memory problems are usually the first thing families notice.

How common it is

Alzheimer's is the most common cause of dementia by a wide margin, responsible for around 60% of dementia diagnoses in the UK. If you're still getting clear on how dementia and Alzheimer's relate to each other, our explainer covers that directly →

Early symptoms

• Difficulty remembering recent conversations, names, or events, while memories from decades ago often stay clear for much longer.
• Repeating questions or stories without realising.
• Misplacing items in unusual places.
• Difficulty finding the right word mid-sentence.
• Losing track of dates, or becoming confused about time.

As it progresses, Alzheimer's typically affects language, reasoning, orientation, mood, and eventually physical abilities like walking and swallowing, in that broad order, though the pace and exact pattern varies person to person.

How it tends to progress

Alzheimer's disease usually progresses gradually and fairly steadily over several years, unlike vascular dementia's more stepwise pattern. Families often describe it as a slow, continuous slope rather than sudden drops, though periods of apparent stability followed by a noticeable step down do still happen, particularly around illness, hospital stays, or major life changes.

What treatment actually looks like

There's currently no cure, but several medications can help manage symptoms, particularly in the earlier stages:

• Cholinesterase inhibitors (donepezil, rivastigmine, galantamine) can help stabilise or modestly improve symptoms for a period, often 6–12 months, by boosting a brain chemical involved in memory and thinking.
• Memantine works differently, and is often added once symptoms progress to the moderate-to-severe stage, sometimes alongside a cholinesterase inhibitor.

A note on the newer drugs you may have read about: lecanemab and donanemab are a genuinely different type of treatment, they target amyloid protein directly rather than just managing symptoms. Both are licensed as medicines in the UK, but as of 2026, NICE has ruled that neither should be routinely funded on the NHS in England and Wales, concluding the benefits shown in trials were too modest to justify the cost. This has been a genuinely disappointing development for many in the Alzheimer's community, and the position may change with future appeals or re-evaluation, but it's worth knowing where things actually stand rather than expecting access that isn't currently there.

A word from The Care Compass

An Alzheimer's diagnosis is heavy news by any measure, and it's completely reasonable to need time to take it in. Understanding what's actually happening, and what current treatment can and can't do, tends to make the road ahead feel a little less unknown, even when it doesn't make it easier.

This article is for general guidance only and does not constitute medical advice. For any questions about diagnosis or treatment options, speak to a GP or specialist directly.

You don’t have to navigate it alone.