Alzheimer's disease is a specific brain condition and the leading cause of dementia in the UK, accounting for about two-thirds of dementia cases. Dementia itself is not a disease but an umbrella term for a range of symptoms affecting memory, thinking, and behaviour.
What Is Dementia?
According to the Alzheimer's Society, an estimated 982,000 people live with dementia in the UK, yet more than a third remain undiagnosed. Dementia describes difficulties with memory or thinking that worsen over time, known as cognitive decline. It is caused by diseases affecting the brain, not by normal ageing.
Symptoms include memory loss (especially recent events), confusion, difficulty with daily tasks like cooking, problems with language and understanding, and changes in behaviour such as anxiety, irritability, or sadness.
What Is Alzheimer's Disease?
Alzheimer's disease is a physical condition that damages the brain, often starting years before symptoms appear. Early signs are mild and do not prevent independent living, but over time the damage leads to dementia. For most people, Alzheimer's begins in the brain's memory region, though rare forms start elsewhere and cause different symptoms.
Key Differences
Dementia can arise from many diseases, including Alzheimer's, vascular dementia, and Lewy body dementia. Alzheimer's is the most common cause, but not all dementia is due to Alzheimer's. While Alzheimer's is a specific brain disease, dementia is the resulting set of symptoms.
