Dementia and Alzheimer's disease: early signs, causes and support

Forgetting a name now and then is common. Dementia is different: it is an ongoing decline in thinking that affects daily life. This review explains the signs of dementia and Alzheimer's disease, what raises the risk, how memory problems are assessed and how families can be supported, using information from the NHS, the World Health Organization (WHO) and MedlinePlus.

1. Introduction

The NHS describes dementia as a syndrome, which means a group of related symptoms, caused by an ongoing decline in brain function. It affects more than memory and is not a natural part of ageing ^[1]. Alzheimer's disease is the most common form and contributes to 60 to 70 percent of cases, according to WHO ^[2]. In 2021 about 57 million people worldwide had dementia, and over 60 percent lived in low- and middle-income countries ^[2].

2. Types of dementia

Besides Alzheimer's disease, WHO lists vascular dementia, dementia with Lewy bodies (abnormal protein deposits in nerve cells) and frontotemporal dementia (damage to the frontal lobes of the brain). Mixed forms are common. Dementia can also follow a stroke, HIV infection, harmful alcohol use, repeated brain injury or nutritional deficiencies ^[2]. MedlinePlus explains that Alzheimer's disease slowly affects memory, reasoning and the ability to do daily tasks ^[3]. Late-onset disease starts at 65 or older, and early-onset disease, which is uncommon, starts before 65 ^[3].

3. Signs and symptoms

Early signs described by WHO, the NHS and MedlinePlus include ^{[1, 2, 3]}:

• Forgetting recent events, conversations or people's names
• Getting lost in familiar places or losing track of time
• Trouble finding words or following what is said
• Difficulty with problem solving, planning or familiar tasks
• Repeating questions
• Changes in mood or personality, anxiety or withdrawal from activities

WHO notes that mood and behaviour changes sometimes appear before memory problems ^[2]. Over time, symptoms usually worsen. In later stages people may need help with personal care and may find it hard to move, eat or communicate ^{[1, 2]}. Some people see or hear things that others do not ^[1].

The NHS points out that memory problems alone are common and can be caused by stress, tiredness, illness or medicines ^[1].

4. Causes and risk factors

The exact cause of Alzheimer's disease is not fully understood. Researchers believe it results from a mix of age-related brain changes, genes, health and lifestyle. Age is the biggest risk factor, and a family history raises risk, though many people with the disease have no family history ^[3].

WHO lists these risk factors for dementia ^[2]:

• High blood pressure, diabetes and obesity
• Depression, poor sleep and social isolation
• Hearing and vision loss
• Stroke and traumatic brain injury
• Smoking, harmful alcohol use and physical inactivity
• Low education and air pollution

5. Diagnosis and assessment

No single test diagnoses Alzheimer's disease. The NHS says a doctor asks about symptoms and may run tests to rule out other conditions ^[4]. MedlinePlus describes a review of medical history and medicines, memory, thinking and problem-solving tests, questions about changes in behaviour and tests to rule out other causes. A referral to a specialist may follow ^[3]. The NHS suggests taking someone who knows you well to the appointment ^[4].

6. Treatment, care and support

There is currently no treatment that stops the disease ^{[3, 4]}. WHO explains that medicines can help manage symptoms for some people, and that non-drug approaches such as physical activity, social engagement, rehabilitation and carer support can improve quality of life ^[2]. The NHS lists changes at home that make daily tasks easier, psychological treatments such as cognitive stimulation therapy and palliative care to support the person and family ^[4]. Early diagnosis helps with planning and access to support, and many people live active lives with dementia ^{[1, 4]}.

Caring for someone can be very stressful. WHO advises carers to take breaks, seek help and manage stress ^[2].

WHO notes that young-onset dementia, which starts before age 65, accounts for up to 9 percent of cases ^[2]. People with dementia are encouraged to stay active, plan ahead, keep up hobbies and join support groups. WHO notes that low awareness of dementia creates barriers to diagnosis and care, and advises carers to seek help from family, friends and professionals ^[2].

7. Prevention and brain health

The NHS says there is no known way to prevent Alzheimer's disease, but the risk of dementia may be reduced or its onset delayed ^[4]. WHO and MedlinePlus suggest ^{[2, 3]}:

• Staying physically active and eating well
• Not smoking and limiting alcohol
• Managing blood pressure, cholesterol and blood sugar
• Treating hearing loss
• Getting enough sleep and staying socially connected

8. When to see a doctor

See a doctor if forgetfulness is increasing, affects daily life or worries you or your family, especially after age 65 ^{[1, 4]}. If you are worried about someone else, encourage them to make an appointment and offer to go along ^[4].

In an emergency, call your local emergency number (112 in India, 911 in the United States).

9. Conclusion

Dementia is a group of conditions that worsen over time, and Alzheimer's disease is the most common. It is not a normal part of ageing, and a timely assessment helps people get support and plan ahead. Managing health risks and staying active may support brain health, and care is guided by your own doctor.