Dementia
Last reviewed Saturday, October 24, 2026Dementia is a group of symptoms caused by diseases that damage the brain, which steadily worsen memory, thinking, communication and the ability to manage daily life. Alzheimer disease is the most common cause. Dementia is more common after 65, but it isn’t a normal part of ageing, and a lot can be done to help.
Also called: Alzheimer’s, its most common cause, which contributes to 60 to 70 in 100 cases. Other forms include vascular dementia, dementia with Lewy bodies and frontotemporal dementia. Young-onset dementia begins before 65.
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Signs and symptoms
- Forgetting recent events, misplacing things, or getting lost in familiar places
- Losing track of time, and trouble making decisions or following conversations
- Difficulty finding words or doing familiar tasks
- Changes in mood, personality or behaviour, sometimes before memory problems
Causes
Diseases such as Alzheimer’s, strokes and other damage to the brain cause dementia. Age is the strongest risk factor. Others include high blood pressure, diabetes, depression, hearing loss, smoking, harmful drinking, inactivity and social isolation, so some risk can be reduced.
Treatment
There is no cure, but care makes a real difference. Physical activity, social contact, activities that keep the mind working, and support for carers improve daily life. A doctor may prescribe medicines that ease some symptoms, and treat blood pressure to limit further damage.
In Nigeria
A 2019 review of nine Nigerian studies, most in the South-west, found dementia in about 5 in 100 older people, more often in women. Families often explain memory loss in spiritual or cultural terms, and may turn to faith leaders or elders first, seeking hospital care when behaviour becomes hard to manage. Stigma leads some older men to hide symptoms. Several teaching hospitals and federal neuropsychiatric hospitals, including in Lagos, Ibadan, Abeokuta and Abuja, run old-age psychiatry services.
Dementia vs normal ageing and delirium
Some slowing with age is expected; dementia goes further and keeps getting worse. Depression in older people can look like dementia. Confusion that comes on suddenly, over hours or days, is delirium, often caused by an infection or a stroke. It needs urgent medical help.
When to get help
See a doctor if memory or thinking problems are getting worse, or a parent is getting lost or struggling with familiar tasks. If someone becomes confused suddenly, call 112 (or 767 in Lagos) or go to the nearest emergency unit. Carers can book a licensed therapist on Mytherapist.ng for themselves, for example for stress and burnout or grief and loss.
Read next
This entry is awaiting clinical review. It’s based on published research and health guidelines, and we’ll update it once a clinician has reviewed it.
