Why the type matters more than families expect
Families are often told simply that a relative has dementia, and left to work out the rest. But the type shapes almost everything that follows: which symptoms come first, how quickly things change, which medicines are safe, and what kind of support helps.
The clearest example is Lewy body dementia, where certain antipsychotic medicines can cause severe reactions. Knowing the diagnosis is not academic in that case; it is a safety matter. If nobody has told you which type has been diagnosed, ask the GP or memory clinic directly.
The main types at a glance
| Type | Roughly how common | What families usually notice first |
|---|---|---|
| Alzheimer's disease | Around two in three cases | Recent memory loss, repeated questions, losing the thread of conversation, difficulty with new information. |
| Vascular dementia | Second most common | Slowed thinking, difficulty planning and concentrating, sometimes a stepped decline after a stroke or series of small strokes. |
| Lewy body dementia | Less common but often missed | Fluctuating alertness, visual hallucinations, movement changes similar to Parkinson's, vivid acting out of dreams. |
| Frontotemporal dementia | Less common, often younger onset | Personality and behaviour change, loss of social inhibition or empathy, or a language problem, with memory relatively intact at first. |
| Mixed dementia | Common in older age | Features of more than one type, most often Alzheimer's alongside vascular damage. |
Proportions are broad indications drawn from published UK sources, not a diagnostic tool. Only a clinician can diagnose.
Alzheimer's disease
The classic pattern: recent memory goes first while long-term memory holds. Someone can describe their wedding day in detail and not recall lunch. As it progresses, language, orientation and judgement are affected, and eventually physical function.
What helps: consistency of routine and of the people providing care, reminiscence and life-story work that plays to the memories still intact, clear visual cues rather than verbal instructions, and one instruction at a time rather than a sequence.
Vascular dementia
Caused by reduced blood supply to the brain, often after a stroke or a series of small ones. The pattern is different: thinking slows and planning becomes hard, sometimes before memory is much affected. Decline can happen in steps rather than gradually, with stable periods between.
What helps: managing the underlying vascular risks with the GP - blood pressure, diabetes, cholesterol, smoking - because that can slow progression. Extra time to answer, and physical rehabilitation where stroke has affected mobility or swallowing.
Lewy body dementia
Distinctive because alertness fluctuates markedly, sometimes within a single day, and because visual hallucinations are common and often not frightening to the person. Movement can be stiff and slow, falls are more likely, and people frequently act out dreams during sleep, sometimes years before other symptoms appear.
What helps: good lighting to reduce misperception, falls prevention, keeping to a settled routine on good days and bad, and not arguing with a hallucination the person finds benign.
Frontotemporal dementia
Often diagnosed in people in their fifties and sixties, and frequently mistaken at first for depression, a midlife crisis or a marriage in difficulty, because the earliest changes are in personality and behaviour rather than memory. Some forms affect language instead, with words and meanings going while everything else holds.
What helps: structure and predictability, environments that reduce the chance of behaviour causing distress to the person or others, specialist input, and honest support for a family who are often much younger and still working. Younger onset dementia also raises practical questions about employment and finances that the memory service can point you towards.
What the diagnosis means when you are choosing care
When you speak to a care home, name the type, not just the word dementia. A home that understands Lewy body fluctuation will not assume a quiet afternoon means deterioration. A home experienced in frontotemporal dementia will not treat disinhibition as bad behaviour. Ask specifically whether the team has cared for people with that diagnosis before, and what they learned from it.