Alzheimer's

What is Alzheimer's disease?

Dementia describes a group of symptoms that appear when brain function declines over time, affecting memory, thinking and behaviour. Alzheimer's is the condition behind most cases, gradually damaging brain cells, often first noticed as trouble remembering everyday chats or things that happened recently.

What are the symptoms of Alzheimer's disease?

Alzheimer's disease develops slowly and can affect several areas of brain function beyond memory alone. As it progresses, symptoms usually become more noticeable and may include:

• memory lapses, such as forgetting a recent chat, mixing up names of people and places, or feeling lost even somewhere familiar
• confusion about time, place or what's happening around you
• difficulty planning ahead, weighing up decisions, or working through a set of steps, such as a recipe
• trouble finding words or following a conversation, a language difficulty known as aphasia, including mixing up languages if you speak more than one
• unsteadiness getting around, needing help with everyday self-care, or struggling with fiddly hand movements like doing up buttons
• shifts in behaviour or personality, such as becoming unusually suspicious, agitated or aggressive
• noticing things that others can't see or hear (hallucinations), or holding beliefs that don't match reality (delusions)
• feeling low or anxious

Family or friends often spot these changes before the person experiencing them does.

What are the causes of Alzheimer's disease and who is at risk?

No single fully confirmed explanation exists for why Alzheimer's disease develops. Current understanding points to two particular proteins, amyloid and tau, building up in the brain: one forms sticky clumps between brain cells, while the other twists into tangled fibres inside them, and together they stop cells communicating properly until the cells eventually die. This damage tends to start around the hippocampus, the brain's memory hub, before spreading further.

Getting older is by far the strongest driver of risk, and the numbers climb steeply with age: around 1 in every 14 people over 65 develop Alzheimer's, rising to roughly 1 in 6 beyond 80. However, it isn't only an older person's condition. About 1 in 13 people living with Alzheimer's first received a diagnosis before the age of 65, sometimes labelled early-onset or young-onset disease.

Beyond age, several other factors are linked to a higher chance of developing Alzheimer's disease:

• having a close relative, such as a parent or sibling, who has had the condition, which raises your own risk by around 10–30%, and further still if several siblings are affected
• carrying a gene variant called APOE-e4, linked to higher risk, although plenty of people with this gene never develop Alzheimer's
• long-term conditions affecting your heart and blood vessels, such as high cholesterol, high blood pressure, diabetes or obesity
• depression that hasn't been treated, bearing in mind low mood can also be a symptom of Alzheimer's rather than only a cause
• smoking
• a past traumatic brain injury
• Down's syndrome
• being of Black or Latin American ethnicity.

Are there different types of Alzheimer's disease?

Alzheimer's disease is sometimes grouped by the age at which it starts. Around 1 in 13 people with the condition are diagnosed before 65, sometimes labelled early-onset or young-onset Alzheimer's, while most people are diagnosed later in life, in what's generally called late-onset disease.

Doctors also describe Alzheimer's as moving through a continuum. Brain changes can be present for years with no outward symptoms, followed by a stage of mild cognitive impairment, where thinking or memory difficulties are noticeable but everyday independence is largely intact. From there, the condition is generally staged as mild, moderate or severe, each bringing a greater loss of independence than the last.

How is Alzheimer's disease diagnosed?

No single test can confirm Alzheimer's disease on its own, and having memory problems doesn't automatically mean you have it. A GP will typically talk through what you've been noticing and your wider medical history, often with help from someone close to you who can point out changes you might not have spotted yourself.

They'll also carry out a physical check-up and a neurological examination, testing things like reflexes and coordination, along with further checks designed to exclude other explanations, such as stress or low mood. These often include:

• blood tests, which can rule out other causes and check for markers linked to Alzheimer's
• cognitive tests, assessing memory, thinking and problem-solving
• a brain scan, most often an MRI (magnetic resonance imaging) scan to look for shrinkage in memory-related brain regions, sometimes alongside a CT (computerised tomography) or PET (positron emission tomography) scan
• a mental health assessment

Where Alzheimer's disease is suspected, a specialist referral usually follows, to look into your symptoms in more depth, arrange any further scans, and draw up a personalised care and treatment plan.

How is Alzheimer's disease treated?

At present, no treatment can cure Alzheimer's disease, and no operation can fix it either. Care instead centres on medicines and practical support designed to ease symptoms and slow the condition's progress where possible. Depending on your situation, this might include:

• cholinesterase inhibitors, a group of drugs including donepezil, galantamine and rivastigmine, which help preserve a brain chemical linked to memory and can ease symptoms for a time
• an NMDA antagonist such as memantine, which dampens the effect of a different brain chemical, glutamate, that can otherwise damage brain cells as the disease advances
• newer antibody drugs, lecanemab or donanemab, given by drip into a vein, which target the amyloid protein directly and may slow progression, although they cannot undo damage that has already happened
• additional medicines aimed at specific symptoms, such as low mood, agitation or seizures.

Beyond medicines, practical adjustments to your home can make daily life easier and safer. You may also be offered cognitive stimulation therapy, group activities and exercises designed to help keep memory, thinking and communication skills as sharp as possible for longer.

When should I see a doctor?

Get in touch with a GP if changes to your memory are worrying you, or if you suspect you or someone close to you may be showing signs of Alzheimer's disease. Where possible, take a close friend or family member along to the appointment, since they may pick up on changes you haven't spotted in yourself.

If it's someone else you're worried about, gently encourage them to book an appointment, and offer to go along for support.