Alzheimer's Disease

Alzheimer's disease is a progressive condition that damages the brain over time. It is the most common cause of dementia, a broad term for a decline in memory and thinking that is severe enough to interfere with daily life. In the brain, abnormal proteins build up as plaques and tangles, and nerve cells gradually stop working and die.

Symptoms develop slowly, often over several years. Many people first notice problems with short-term memory, such as forgetting recent conversations or appointments, while older memories remain clearer until later. Alzheimer's disease is not a normal part of ageing, even though the risk rises with age.

Early symptoms usually involve memory, especially for recent events, along with trouble finding the right words, repeating questions, and misplacing items. People may struggle with planning, decision-making, and following familiar routines such as cooking or managing money.

As the disease advances, memory loss deepens and confusion about time and place becomes more common. Mood and behaviour can change, with anxiety, low mood, agitation, or withdrawal. In later stages, people need more help with everyday activities such as eating, dressing, and moving around.

The exact cause is not fully understood, but it is linked to the build-up of plaques and tangles in the brain that disrupt how nerve cells communicate. This process likely begins years before symptoms appear.

Age is the strongest risk factor, and most cases occur after 65. Family history, certain genes, and conditions that affect heart and blood vessel health, such as high blood pressure, diabetes, and smoking, can also raise the risk. Less commonly, a rare inherited form can cause symptoms before age 65.

There is no single test for Alzheimer's disease. A doctor starts by reviewing symptoms, medical history, and often information from a family member, then carries out memory and thinking tests to measure how different areas of cognition are affected.

Blood tests and brain scans such as MRI or CT are used to look for other conditions that can cause memory problems, including thyroid disease, vitamin deficiencies, infection, or stroke. In some cases, specialised scans or fluid tests may be used to support the diagnosis. Identifying the cause matters, because some conditions that mimic dementia are reversible.

There is currently no cure, but treatment can help with symptoms and daily life. Some medicines may improve or stabilise memory and thinking for a time in certain people, and others can help with mood, anxiety, or sleep when needed. Treatment is tailored to the individual and reviewed regularly.

Non-medical support is just as important. Regular routines, memory aids, a safe and familiar environment, physical activity, and social contact can all help. Managing other health conditions, planning ahead for care and finances, and connecting with support services for both the person and their carers can make a meaningful difference over time.

Alzheimer's disease cannot reliably be prevented, but a healthy lifestyle may lower the risk or delay onset. This includes staying physically active, keeping the mind and social life engaged, eating a balanced diet, not smoking, limiting alcohol, and managing blood pressure, diabetes, and hearing loss.

The outlook varies from person to person. Alzheimer's disease is progressive, and symptoms increase gradually over years, but the pace differs widely. With the right support, many people continue to do things they value for a long time. A sudden worsening of confusion is not typical of Alzheimer's and should be checked promptly, as it may signal another problem such as infection.