What is Alzheimer's Disease?

Are you finding yourself forgetting things more often lately? Are you concerned it might be Alzheimer’s? You’re not alone; Alzheimer’s is one of the most common forms of dementia, affecting:

●     5% of people aged 65–74

●     13% of people aged 75–84

●     33% of people aged 85 and older

What Causes Alzheimer’s?

Alzheimer’s disease is characterized by the abnormal accumulation of amyloid-beta plaques and tau protein tangles in the brain. These changes are closely associated with disrupted neural communication and progressive damage to brain cells.

Mild-Stage Alzheimer’s

This is the phase where symptoms are the least noticeable, often simply mistaken for the symptoms of old age. You can function independently and feel comfortable taking part in social activities. According to the GDS Model of the seven clinical stages of Alzheimer’s, this phase can be divided into three further stages:

●     The first clinical stage is healthy, the point before any symptoms or disease emerges.

●     The second clinical stage is subjective cognitive decline, signaled by the repeated occurrence of memory loss; this is when you start forgetting things like names or the locations of items from time to time.

●     The third stage is mild cognitive impairment; this is when forgetfulness becomes more obvious. This can come up as asking someone to repeat what they just said multiple times or forgetting how to do a task you have done for years.

Moderate-Stage Alzheimer’s

In this stage forgetfulness increases, and symptoms of dementia will start to appear. You may start to forget daily tasks and often feel confused about the correct date. Frustration and anger arise more easily, as Alzheimer's makes it more difficult to express your thoughts and emotions. The GDS divides it into two clinical stages:

●     The fourth stage is moderate cognitive decline; memory loss becomes evident as complex tasks in day-to-day life become much harder to accomplish. Unfortunately, a key symptom at this point of Alzheimer’s is the denial of memory decline, a defense mechanism triggered by your awareness of your own mental decline.

●     The fifth stage is moderately severe cognitive decline; at this stage, you can no longer live without assistance. You may start wandering, finances will start being hard to manage, and you become much more susceptible to predatory strangers.

Even in these stages, you can still participate in daily and social activities, but you may need more help. Care homes are often considered towards the fifth stage, as you start to need more and more assistance.

Severe-Stage Alzheimer’s

This is the stage where dementia becomes debilitating. You will need to rely entirely on caregivers and care homes as you start to lose many functions, including your ability to talk and respond to the world around you. This is split by the GDS divides this into two stages:

●     The sixth stage is severe cognitive decline; this is where you lose the ability to bathe without assistance and to use the toilet unsupervised, become incontinent and where your ability to speak starts to break down. Your memory will become unclear, to the point of mixing up the people in your life, physical activity will start to take a significant strain on your body.

●     The seventh and final stage is very severe cognitive decline; assistance is now needed for basic activities, your ability to speak deteriorates severely, and a common symptom that arises is the rigidity of joints, due to your muscles tensing up, making it much more difficult to move.

When to seek diagnosis?

 Seeking medical help is most beneficial during clinical stages 3 and 4, as Alzheimer's in these stages can be detected with high accuracy, using medical testing to help clarify the cause. For example, blood-based tests such as PrecivityAD2 can detect the proteins related to Alzheimer’s disease with high accuracy. It’s especially useful for people over 50 who want answers without undergoing invasive procedures such as a CSF tap or a PET scan.  PET scans are not always available between medical facilities, and the test also requires the patient to lie still in the machine for 20 to 60 minutes. Instead, it just requires a blood sample.  Early diagnosis is important, as most, if not all, of your brain function is still intact; the test will identify the causes of your problems, whether it’s Alzheimer’s or not, and if so, treatments can usually slow down the progression of mental decline.

Alzheimer’s is a brutal disease, robbing a person of their mental and physical abilities, but it is important to note that it presents itself differently in everyone. These stages are only guidelines, and if you are concerned about your health, you should always consult with a doctor or another professional.

Getting a diagnosis early on is crucial; if you do have Alzheimer’s, it is best to realize it early on. This gives treatment more time to help slow and limit the progression of cognitive decline.

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Reference

1. Reisberg, Barry, et al. An Atlas of Alzheimer's Disease. Edited by Mony J. De Leon, Taylor & Francis, 1999. Accessed 22 October 2025.

2. “Stages of Alzheimer's”, alz.org, alz.org/alzheimers-dementia/stages. Accessed 22 October 2025

3. “Clinical Stages of Alzheimer's”, alzinfo.org, alzinfo.org/understand-alzheimers/clinical-stages-of-alzheimers/, Accessed 22 October 2025