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

Dementia is the name for a group of symptoms, an ongoing decline in brain functioning affecting memory, thinking skills and other mental abilities. Alzheimer's disease is a physical illness of the brain and the most common reason someone develops those symptoms. Alzheimer's Society puts it simply: Alzheimer's is a disease in the brain, whereas dementia is a collection of symptoms.

Early on, symptoms are mild and do not stop someone managing everyday activities alone. Alzheimer's Society calls this stage mild cognitive impairment, and notes that at this point it is often not possible to say for sure that Alzheimer's is the cause. Dementia is the label used once the problems make everyday tasks difficult.

The NHS divides symptoms into three main stages, with the pace differing for each person. Infections, a stroke, delirium and certain medicines can make symptoms worse, so the NHS says anyone whose symptoms are getting worse rapidly should be seen by a doctor, as there may be a treatable reason.

Alzheimer's Society describes less common "atypical" forms where the disease starts elsewhere in the brain. It names four main types: one mostly affecting language (logopenic aphasia), one affecting vision and spatial judgement (posterior cortical atrophy), a frontal variant affecting behaviour or thinking, and one causing movement and sensation problems along with changes in thinking (corticobasal syndrome). The NHS likewise says the first symptoms in more unusual forms may be problems with vision or language rather than memory. If a relative has trouble with reading, judging steps or finding words before forgetting things, say so at the appointment.

The NHS describes an abnormal build-up of two proteins: amyloid, which forms plaques around brain cells, and tau, which forms tangles inside them. Levels of the messenger chemical acetylcholine fall, and areas of the brain shrink, usually starting with those responsible for memories.

Age is the single most significant risk factor. Family history contributes a small increase in risk, though in a few families a single inherited gene is responsible and the NHS suggests genetic counselling if several relatives developed dementia, particularly young. People with Down's syndrome are at higher risk, and a severe head injury may raise it. The NHS also links smoking, obesity, diabetes, high blood pressure and high cholesterol with higher risk, and lists hearing loss, untreated depression, loneliness or social isolation and a sedentary lifestyle among other factors that research suggests matter.

The usual first step is a GP appointment, ideally with someone who knows the person well to describe changes. The NHS says there is no single test for Alzheimer's and that memory problems do not necessarily mean Alzheimer's; the GP asks about problems and may do tests to rule out other conditions. Memory problems can also come from depression, stress, medicines or other health problems.

If dementia is suspected, Alzheimer's Society says the GP refers to a local memory service, where a specialist health professional usually makes the diagnosis. The NHS says specialist services can assess symptoms in more detail, arrange brain scans where needed, and create a treatment and care plan. Alzheimer's Society offers a printable symptom checklist to take to the GP.

The NHS names donepezil, galantamine and rivastigmine (also available as a patch) for early to mid-stage disease; these can currently only be started by specialists, and current guidance is that they should be continued in the later severe stages. Side effects can include nausea, vomiting and loss of appetite, usually improving after about 2 weeks. Memantine is used for moderate or severe disease, or where the first group cannot be taken, and can cause headaches, dizziness and constipation. These medicines temporarily relieve symptoms; they do not stop the disease.

Non-drug approaches are described as just as important: cognitive stimulation therapy in groups, cognitive rehabilitation with an occupational therapist working towards a personal goal, and reminiscence or life story work, which the NHS says evidence shows can improve mood and wellbeing. For distressing behaviours in later stages, the NHS says coping strategies come first, and that antipsychotics, which have serious side effects, should be used at the lowest dose for the shortest time and only under a consultant psychiatrist. Because many older people take several medicines, any new prescription should be reviewed alongside the existing list.

The NHS says people can live for several years after symptoms begin, though this varies a great deal; it is a life-limiting illness, although many people die from another cause. As it progresses, swallowing problems can lead to food being inhaled into the lungs, causing frequent chest infections, and eating difficulties and reduced appetite become common. The NHS notes that people with Alzheimer's need palliative care, including support for families.

Practical planning is easier early: talking about future wishes, legal arrangements and support while the person can still take part. Carers can also take part in dementia research through the NHS Join Dementia Research service, and the NHS points families to guidance on staying independent, communicating, and coping with behaviour changes.