Understanding Alzheimer’s disease and other types of dementia
By Cynthia Lodite, July 11, 2026Alzheimer’s disease is the most common cause of dementia, but it is not the only one. Dementia is an umbrella term for a group of conditions that affect memory, thinking, behaviour and the ability to perform everyday tasks.
Understanding the different types can help families recognise symptoms early and seek appropriate medical care.
According to the World Health Organization, more than 57 million people worldwide are living with dementia, with nearly 10 million new cases diagnosed each year. While age is the biggest risk factor, dementia is not a normal part of ageing.
“In 2021, 57 million people were living with dementia worldwide, over 60 per cent of whom live in low-and middle-income countries. Every year, there are nearly 10 million new cases,” WHO stated.
At the same time, WHO notes that Dementia results from a variety of diseases and injuries that affect the brain. Alzheimer disease is the most common form of dementia and may contribute to 60–70 per cent of cases.
Alzheimer’s disease
Alzheimer’s disease accounts for around 60 to 70 per cent of dementia cases. It gradually damages brain cells, leading to memory loss, confusion and difficulty with language and problem-solving.
Early signs may include forgetting recent conversations, misplacing items, struggling to find the right words or becoming confused about time and place. As the disease progresses, people may need increasing support with daily activities such as dressing, eating and personal care.
Other common types of dementia
Not all dementia follows the same pattern. Different types affect the brain in different ways.
Vascular dementia develops when reduced blood flow damages the brain, often after a stroke or because of conditions such as high blood pressure. People may experience difficulties with planning, decision-making and concentration alongside memory problems.
Lewy body dementia is linked to abnormal protein deposits in the brain. It can cause changes in attention, visual hallucinations, sleep disturbances and movement problems similar to those seen in Parkinson’s disease.
Frontotemporal dementia usually affects younger adults than Alzheimer’s disease, often before the age of 65. It primarily changes personality, behaviour and language rather than memory in its early stages.
Some people may also have mixed dementia, where more than one type of dementia occurs at the same time, commonly Alzheimer’s disease alongside vascular dementia.
Why early diagnosis matters
There is currently no cure for most forms of dementia, but early diagnosis allows people and their families to plan for the future, access treatment that may help manage symptoms and receive support services sooner.
Anyone experiencing persistent memory loss, confusion or noticeable changes in thinking or behaviour should seek medical evaluation. These symptoms can sometimes be caused by treatable conditions such as vitamin deficiencies, medication side effects or thyroid disorders.
Although dementia becomes more common with age, healthy lifestyle habits including regular physical activity, a balanced diet, managing blood pressure, staying socially connected and keeping the mind active may help lower the risk.
Recognising the signs early and seeking professional advice can make a meaningful difference to quality of life for both the individual and their loved ones.