Dementia and Alzheimers Disease: Early Signs, Treatable Causes and the Medicines That Help
People often use "dementia" and "Alzheimers" as if they mean the same thing. They do not. Dementia is the general term for a decline in memory, thinking and daily functioning severe enough to affect independence. Alzheimers disease is the most common cause of it, but there are several others, and they behave and are treated differently.
Dementia is not a normal part of ageing. Occasional forgetfulness is; losing the ability to manage money, find your way home or follow a conversation is not. And some memory problems that look like dementia turn out to have a cause that can be treated.
This guide explains the main types, the early signs, the treatable conditions that mimic dementia, what current medicines can and cannot do, and what lowers the risk.
🧠 The main types
| Type | Typical features |
|---|---|
| Alzheimers disease (about 60 to 70 percent) | Gradual loss of recent memory first, then language, orientation and planning. Slow, steady progression |
| Vascular dementia | Caused by strokes or damage to small blood vessels. Often stepwise decline, slowed thinking, problems with planning more than memory |
| Dementia with Lewy bodies | Fluctuating alertness, vivid visual hallucinations, Parkinson-like stiffness, acting out dreams during sleep |
| Frontotemporal dementia | Often starts younger. Changes in personality and behaviour, or in language, before memory |
| Mixed dementia | Alzheimers plus vascular changes; very common in older people |
🔍 Normal ageing or something more?
| Usually normal with age | May be a sign of dementia |
|---|---|
| Forgetting a name, then remembering it later | Forgetting recent events or conversations and not recalling them at all |
| Occasionally misplacing keys | Putting things in odd places and being unable to retrace steps |
| Taking longer to learn new technology | Struggling with familiar tasks such as cooking a known recipe or paying bills |
| Searching for a word now and then | Frequent trouble following or joining conversations |
| Feeling tired of social obligations | Withdrawing, losing initiative, or marked personality changes |
| Momentary confusion about the day | Getting lost in familiar places |
Often it is a family member, not the person themselves, who notices the change first. Their observations are one of the most valuable parts of the assessment.
✅ Treatable conditions that can look like dementia
Before a dementia diagnosis is made, doctors look for conditions that affect memory and thinking but can improve with treatment.
- Depression
- Can cause slowed thinking, poor concentration and memory complaints that improve when mood is treated. Our guide to depressive pseudodementia explains the difference.
- Medicines
- Drugs with anticholinergic effects commonly cloud thinking in older people: some bladder medicines such as oxybutynin, older antihistamines, tricyclic antidepressants, and several sleep aids. Oxybutynin is in our catalogue as Ditropan (Oxybutynin), and it is one to review if memory worsens.
- Vitamin B12 deficiency and underactive thyroid
- Both are found with simple blood tests and treated easily.
- Delirium
- Sudden confusion, often from an infection, dehydration or a new medicine. It comes on over hours or days and needs urgent attention.
- Hearing loss and sleep apnoea
- Both impair attention and memory, and both are treatable.
- Normal pressure hydrocephalus
- A build-up of fluid in the brain causing a shuffling walk, bladder problems and slowed thinking. Can improve with surgery.
🔬 How it is diagnosed
Assessment starts with a detailed history from the person and someone who knows them well, followed by memory and thinking tests, a physical examination, and blood tests for the treatable causes above. A brain scan looks for strokes, tumours or patterns of shrinkage. In some cases, specialised tests detect the proteins linked to Alzheimers in spinal fluid, on a special PET scan, or increasingly with blood tests. These are becoming more important now that some treatments are only suitable when these proteins are confirmed.
💊 Medicines for symptoms
Two groups of medicines can ease symptoms of Alzheimers disease for a time. They do not stop the underlying disease, but many people and families notice steadier memory, attention and daily function for months to a year or more.
| Medicine | Used for | Practical points |
|---|---|---|
| Donepezil | Mild to severe Alzheimers disease; also helps Lewy body dementia | Once daily, usually starting at 5 mg and increased to 10 mg after four to six weeks. Taken at night; switch to morning if dreams are vivid |
| Rivastigmine | Mild to moderate Alzheimers disease and Parkinson or Lewy body dementia | Capsules or a skin patch; the patch causes less nausea |
| Memantine | Moderate to severe Alzheimers disease, alone or with donepezil | Works on a different brain chemical; generally well tolerated |
In our Alzheimers and dementia category these are available as Aricept (Donepezil), Exelon (Rivastigmine) and Namenda (Memantine). How memantine works and what to expect is covered in our memantine guide.
⚠️ Side effects of donepezil and rivastigmine include nausea, diarrhoea, loss of appetite, muscle cramps and vivid dreams, usually worst when starting or increasing the dose. They can also slow the heart rate, which may cause dizziness or fainting, especially with beta-blockers. Report fainting or a very slow pulse. These medicines are not helpful in frontotemporal dementia and can worsen behaviour there.
🧪 Newer treatments that target the disease
Antibody treatments that remove amyloid, one of the proteins that builds up in Alzheimers disease, have been approved in some countries for people in the early stage with confirmed amyloid. In trials they slowed decline modestly over about eighteen months. They are given by infusion, need regular MRI scans because they can cause brain swelling and small bleeds, and carry higher risk in people with a particular gene variant. They are prescribed by specialist memory services and are not in our catalogue. Anyone with early symptoms who is interested should ask for referral promptly, since the window for treatment is early.
🚫 Medicines to be cautious with
Agitation, distress and hallucinations are common in later dementia. Antipsychotic medicines are sometimes used for severe, distressing symptoms, but they raise the risk of stroke and death in people with dementia, so they are a last resort, at the lowest dose and for the shortest time. People with Lewy body dementia can react dangerously to them. Sedating sleep medicines increase falls and confusion. First, look for pain, infection, constipation, hunger, noise or boredom, which often drive behaviour changes.
🛡️ What lowers the risk
Research suggests nearly half of dementia cases worldwide may be linked to factors that can be changed. Acting on them in midlife and later helps.
- 👂 Treat hearing loss — hearing aids appear to reduce risk
- 🩺 Control blood pressure, especially in midlife; options are in our blood pressure category
- 🧈 Lower high LDL cholesterol
- 🚬 Stop smoking
- 🏃 Stay physically active
- 🩸 Manage diabetes and weight
- 🍷 Keep alcohol low
- 👥 Stay socially connected and mentally engaged
- 👀 Treat vision problems such as cataracts
- 🪖 Protect the head from injury, and treat depression
🤝 Living with dementia and caring
A diagnosis is a lot to take in, but it also opens the door to support, treatment and planning while the person can still take part in decisions.
- Plan early
- Discuss wishes about care, finances and legal decisions such as power of attorney while the person can express them.
- Keep routines
- A predictable day, good lighting and fewer distractions reduce confusion.
- Manage medicines safely
- Pill organisers, blister packs and supervision prevent missed doses and accidental double doses.
- Review driving
- Dementia affects judgement and reaction time. Most countries require the diagnosis to be reported for driving.
- Prevent wandering and falls
- Door alarms, identification bracelets and removing trip hazards help.
- Support the carer
- Caring is exhausting. Respite, carer groups and help with daily tasks protect the carer's own health.
📞 When to see a doctor
- Memory or thinking changes that affect daily life, noticed by you or others
- Sudden confusion over hours or days — urgent, it may be delirium
- Getting lost, repeating questions, or trouble with familiar tasks
- Personality or behaviour changes, especially under 65
- Hallucinations, fluctuating alertness or acting out dreams
- Fainting or a slow pulse on donepezil or rivastigmine
- Carer struggling to cope
❓ Frequently asked questions
What is the difference between dementia and Alzheimers?
Dementia is the general term for a decline in memory and thinking that affects independence. Alzheimers disease is the most common cause of dementia, accounting for about 60 to 70 percent of cases. Other causes include vascular dementia, Lewy body dementia and frontotemporal dementia.
What are the early signs of dementia?
Forgetting recent events and conversations, repeating questions, trouble with familiar tasks such as bills or cooking, getting lost in familiar places, difficulty following conversations, and changes in mood or personality. Family members often notice first.
Can memory loss be caused by something treatable?
Yes. Depression, vitamin B12 deficiency, an underactive thyroid, medicine side effects, delirium from infection, hearing loss, sleep apnoea and normal pressure hydrocephalus can all affect memory and may improve with treatment.
Does donepezil slow Alzheimers disease?
It does not stop the disease, but it can improve or stabilise memory, attention and daily function for a period, often months to a year or more. It is started at 5 mg and usually increased to 10 mg after four to six weeks.
What are the side effects of donepezil?
Nausea, diarrhoea, loss of appetite, muscle cramps and vivid dreams are the most common, especially early on. It can slow the heart rate, causing dizziness or fainting, so a slow pulse or fainting should be reported.
What is the difference between donepezil and memantine?
They work on different brain chemicals. Donepezil is used across all stages of Alzheimers disease, and memantine in moderate to severe stages. They are often combined in later stages.
What are the new Alzheimers antibody treatments?
Infused antibodies that remove amyloid protein, approved in some countries for early Alzheimers with confirmed amyloid. They slow decline modestly but need regular MRI monitoring because of a risk of brain swelling and small bleeds. They are given by specialist services.
Can dementia be prevented?
Not always, but risk can be reduced. Treating hearing loss and high blood pressure, lowering cholesterol, not smoking, staying active, managing diabetes, limiting alcohol and staying socially engaged are linked to lower risk.
Is sudden confusion a sign of dementia?
Sudden confusion over hours or days is more often delirium, caused by infection, dehydration or a new medicine. It needs urgent medical assessment. Dementia usually develops gradually over months or years.
Why are antipsychotics risky in dementia?
They increase the risk of stroke and death in people with dementia, and people with Lewy body dementia can react severely. They are used only as a last resort for severe distress, at the lowest dose and for the shortest time.
📑 Sources and editorial
- Clinical guidelines on the assessment and management of dementia
- Prescribing information for donepezil, rivastigmine and memantine
- Trials and regulatory assessments of anti-amyloid antibody treatments
- Commission report on modifiable risk factors for dementia
- Guidance on anticholinergic burden and cognition in older adults
- Regulatory warnings on antipsychotics in older people with dementia
- Related reading: memantine, depressive pseudodementia
- Related products: Aricept (Donepezil), Exelon (Rivastigmine), Namenda (Memantine)
- RXshop Editorial Team — reviewed by James Carter, MD, Neurology
Medical Disclaimer: The information in this article is for educational and informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek guidance from a qualified healthcare provider with any questions you may have regarding a medical condition, and before starting, stopping or changing any medication.