There are different types of dementia, that is why there are different communication types and issues. For example, some people, suffering from dementia, experience difficulties with communication and usually lack on words to express themselves. On the other hand, there are people who will be very talkative while suffering from dementia, but still, everything they say won't have any sense.
Investigations say, that those people can find another type of communicating and expressing themselves, but they might need professional help for that. Carers are teaching them to use the tone of voice, facial expressions, general body language and gestures and eye contact to communicate.
Also, there are more troubles in communication, when a person, suffering from dementia has some type of sensory disorder: visual, hearing, smell, touch or taste.
A visual disorder usually means visual distortions, even though the eyes are physically healthy. So, people with dementia won't be able to recognize what they see, but that is only because of the changes in their brain.
A hearing disorder is also not about ears health. It is about having difficulties in understanding what other people say.
The complete or partial loss of smell is quite usual for people, who suffer from dementia. So they might face difficulties in expressing what they feel.
Touch disorder is also common. People with dementia can completely or partially lose the ability to feel the temperature of objects or their own body. So, they won't be able to tell whether something is too cold or hot. Or, on the contrary. They will be oversensitive to the temperature, but won't tell about the discomfort, even though experiencing it.
Taste disorder is about losing taste sensitivity. People with dementia may start putting practically anything to their mouth when feeling hunger, or on contrary, stop eating at all, even when feeling hunger. Even though they won't be able to explain that.