In most cases, the symptoms of dementia progress gradually, over a period of several years. The early signs, usually memory problems, are normally subtle and may not be immediately obvious.

The symptoms of dementia can vary greatly, but those with the conditoion often have one or more of the symptoms outlined below.

Memory problems

People with dementia may have memory problems; they may forget the names of people they know well, or they may forget where they live. Normally, recent memories are affected first, with memories of events further in the past only affected once the dementia becomes more developed.

As dementia progresses, memory loss may affect memories of recent events so completely that the person appears to be 'living in the past'. They may even think of themselves as young and not recognise their true age.

Speech and language problems

People with dementia may forget simple words, they may use the wrong words without noticing, or their conversation may become simplified, repetitive, or irrelevant.

Confusion

People with dementia may become confused in new surroundings, or by new people, or about who, or where, they are. They may lose track of time so that they are unsure what day it is, or even whether it is morning or afternoon.

Changes in mood or behaviour

Those with dementia may become irritable or aggressive. As dementia progresses, they may lose their normal inhibitions and begin to say, or do, things that are inappropriate, or antisocial.

In some cases, this can include inappropriate sexual behaviour. They may lose interest in the outside world or their own care, giving up interests and hobbies, paying little attention to their personal hygiene, or forgetting to wash or change their clothes.

Problems performing simple tasks

Everyday tasks, such as cooking a meal, may be difficult for people with dementia. They may begin cooking and then wander away, forgetting what they were doing, or they may prepare a meal and then forget to serve it.

THose with dementia may also expereice problems learning new information, ideas, or skills.

Less common symptoms

Some types of dementia can cause less common symptoms including:

• hallucinations,
• obsessive or repetitive behaviour,
• the belief that they have done or experienced things that never happened (confabulation),
• disturbed sleep, or sleeping in the daytime and being awake at night,
• depression,
• physical deterioration, loss of appetite, loss of weight and increased vulnerability to infection, and
• incontinence.

If dementia becomes severe, it can cause other symptoms, including:

• difficulty with swallowing,
• difficulty changing position or moving from place to place without assistance, and
• complete loss of short-term and long-term memory.

Sometimes, those with dementia are unaware that they have any symptoms, especially symptoms that affect behaviour.

Many conditions (such as depression) have symptoms similar to dementia, so it is important not to assume that someone has dementia just because they have some of the symptoms above.