It's common for people with Alzheimer’s to also have vascular dementia, which is caused by reduced blood flow to the brain. People suffering with both types are referred to as suffering from mixed dementia.
Alzheimer’s is caused by parts of the brain shrinking , which alters how it normally functions. Changes in the brain lead to the build-up of two proteins , amyloid and tau. These proteins form structures called ‘plaques’ and ‘tangles’ which are linked with a loss of connections between nerve cells, this leads to the death of nerve cells and loss of brain tissue.
People with Alzheimer’s also lack the important components of the chemical messengers in our brain that transmit signals needed for thinking and communicating. What triggers these changes is still not fully understood.
Alzheimer's develops slowly over several years and the early signs can be hard to distinguish from normal ageing symptoms, such as mild forgetfulness.
Typical early stage symptoms include: forgetting recent events, names, faces and places; problems finding the right word; becoming increasingly repetitive; confusion and disorientation; poor decision-making; low mood, anxiety and irritability.
Mid-stage symptoms include: worsening memory problems, confusion and disorientation; finding it harder to communicate; not being able to recognise familiar objects and faces; delusions, hallucinations and paranoia, and changes in sleeping pattern.
In the late stages, memory loss becomes more noticeable and difficulties with swallowing and eating, poor mobility, incontinence and speech loss develop.
While there's no cure for Alzheimer’s, having it diagnosed early gives access to treatment and support as well as help with planning for the future.
Your GP can carry out some simple memory checks and then refer you or your relative to a memory clinic or specialist for further tests.
To look for signs of damage caused by Alzheimer’s in your brain, you need a CT or MRI scan.
As there is no definitive test for Alzheimer’s, it can take several appointments and repeated memory tests over many months to get a diagnosis.
Who gets it?
Age is the biggest risk factor for developing Alzheimer’s, and the chances of having it double every five years after age 65. One in six people over age 80 has Alzheimer’s, however, one in 20 people who develop it are under 65. This is called early-onset Alzheimer’s and affects people from age 40.
There are twice as many women as men over 65 with Alzheimer’s. This is partly down to the fact that women live longer, but could also possibly be linked to the drop in the hormone oestrogen after the menopause.
Early-onset Alzheimer's can develop from inherited genes, but generally only one in 100 Alzheimer’s cases is linked to faulty genes.
The risk factors associated with cardiovascular (heart and circulatory) disease also increase the risk of Alzheimer’s, these including smoking, obesity, diabetes, high blood pressure and high cholesterol, so taking steps to address all these can help to reduce your risks. For instance, smoking is said to increase the risk of developing Alzheimer’s by 50 to 80 per cent.
There's good evidence from experiments with mice that exercise, particularly aerobic exercise, reduces the risk of Alzheimer's, but more research is needed.
Drug treatments can't cure Alzheimer’s but in some people they stabilise symptoms for a while.
Cholinesterase inhibitors include: donepezil (Aricept), rivastigmine (Exelon) and galantamine (Reminyl), help to send messages between nerve cells, improving or stabilising symptoms for six to 12 months and are prescribed for mild to moderate Alzheimer’s.
NMDA receptor antagonists (memantine) are drugs prescribed for late stage Alzheimer's and work by blocking the effects of excess glutamate (a chemical that sends messages between nerve cells), released by damaged brain cells.
A 2017 study in Scotland found that older people who ate a Mediterranean-style diet had less brain shrinkage. This could potentially reduce the risk of Alzheimer’s.
Studies on the use of vitamin D supplements to treat and prevent Alzheimer’s also look promising.