The word dementia describes a set of symptoms that may include memory loss and difficulties with thinking, problem-solving or language. Dementia is caused when the brain is damaged by diseases, such as Alzheimer’s disease or a series of strokes.
The term ‘dementia’ is used to describe the symptoms that occur when the brain is affected by specific diseases and conditions. There are over 100 different types of dementia.
All types of dementia are progressive. This means that the structure and chemistry of the brain become increasingly damaged over time.
Dementia is caused when the brain is damaged by diseases, such as Alzheimer’s disease or a series of strokes. Alzheimer’s disease is the most common cause of dementia but not all dementia is due to Alzheimer’s. The specific symptoms that someone with dementia experiences will depend on the parts of the brain that are damaged and the disease that is causing the dementia.
Each person is unique and will experience dementia in their own way. The different types of dementia tend to affect people differently, especially in the early stages. How others respond to the person, and how supportive or enabling the person’s surroundings are, also greatly affect how well someone can live with dementia.
A person with dementia will have cognitive symptoms (problems with thinking or memory). They will often have problems with some of the following:
- day-to-day memory – difficulty recalling events that happened recently
- concentrating, planning or organising – difficulties making decisions, solving problems or carrying out a sequence of tasks (eg cooking a meal)
- language – difficulties following a conversation or finding the right word for something
- visuospatial skills – problems judging distances (eg on stairs) and seeing objects in three dimensions
- orientation – losing track of the day or date, or becoming confused about where they are.
As well as these cognitive symptoms, a person with dementia will often have changes in their mood. For example, they may become frustrated or irritable, withdrawn, anxious, easily upset or unusually sad.
With some types of dementia, the person may see things that are not really there (visualhallucinations) or believe things that are not true (delusions).
Dementia is progressive, which means the symptoms gradually get worse over time. How quickly dementia progresses varies greatly from person to person.
As dementia progresses, the person may develop behaviours that seem unusual or out of character. These behaviours may include repetitive questioning, pacing, restlessness or agitation. They can be distressing or challenging for the person and their carer.
A person with dementia, especially in the later stages, may have physical symptoms such as muscle weakness or weight loss. Changes in sleep pattern and appetite are also common.