Alzheimer's disease: symptoms, stages, diagnosis and treatment

Alzheimer's disease is a physical illness that damages the brain. Dementia is the name for the group of symptoms, affecting memory, thinking and other abilities, that results from it. The Alzheimer's Society explains that a key part of the disease is the build-up of two substances, amyloid and tau, which clump into plaques and tangles that make it harder for the brain to work. It starts many years before symptoms appear.

The NHS says the exact cause is not fully understood. Risk factors include increasing age, a family history, untreated depression (although depression can also be a symptom) and lifestyle factors and conditions associated with cardiovascular disease. The Alzheimer's Society notes that above 65 the risk roughly doubles about every five years.

The NHS describes three broad stages, with the rate of change differing for each person.

For most people Alzheimer's begins in the part of the brain involved in memory, but the Alzheimer's Society describes rarer atypical forms that do not cause memory problems at first. Four main types are named: one mainly affecting language (logopenic aphasia), one affecting vision and spatial judgement (posterior cortical atrophy), one affecting behaviour or thinking (frontal variant), and one affecting movement and sensation as well as thinking (corticobasal syndrome).

Around 1 in 13 people with Alzheimer's are under 65, which the NHS calls early- or young-onset Alzheimer's disease.

Because symptoms progress slowly, many people assume memory problems are part of getting older, and the disease itself may stop people noticing changes. The NHS suggests seeing a GP if you are worried, ideally with someone who knows you well. There is no single test. A GP asks questions and may do tests to rule out other causes such as depression, stress, medicines or other health problems. If dementia is suspected, referral is to a local memory service or specialist for a more detailed assessment, further testing such as brain scans if necessary, and a treatment and care plan.

The Alzheimer's Society says diagnosis is usually made by a specialist health professional and that an early diagnosis gives time to adjust and get the support you need. The NHS says a timely diagnosis offers the best chance to prepare and plan for the future.

The NHS says there is no cure but medicines can temporarily improve symptoms. Acetylcholinesterase inhibitors, which are donepezil, galantamine and rivastigmine (also available as a patch), are for early to mid-stage disease and are usually started by specialists. Side effects can include nausea, vomiting and loss of appetite, and the NHS says these usually settle after about 2 weeks. Memantine is used for moderate or severe disease, or when the first group cannot be taken or tolerated.

Non-drug approaches matter just as much. The NHS lists cognitive stimulation therapy (group activities designed to support memory and problem-solving), cognitive rehabilitation with a trained professional such as an occupational therapist, and reminiscence and life story work. Antipsychotics are reserved for persistent aggression or extreme distress that puts someone at risk, at the lowest dose for the shortest time, because of serious side effects.

The NHS says infections, stroke, delirium and some medicines can make symptoms of dementia worse, and that anyone whose symptoms are rapidly getting worse should be seen by a doctor, because there may be treatable reasons. A sudden change in confusion should be treated as a medical question rather than assumed to be progression.

The NHS says people can live for several years after symptoms begin, varying a great deal between individuals. It describes Alzheimer's as life-limiting, with many people dying from another cause, and says increasing awareness of the need for palliative care, including support for families. Swallowing problems can lead to inhaled food and recurrent chest infections, and difficulty eating is common later on. Many families find it easier to talk about care preferences and practical arrangements early, while the person can still take part in decisions.

The NHS route is GP, then memory service, then ongoing community support. Private memory clinics offer assessments, scans and specialist opinions, sometimes sooner. If a private diagnosis is made, ask how it will connect to NHS medicines, monitoring and community support afterwards.