With all three types of PPA, problems get worse over time. It becomes harder for people to say what they need and move about on their own.

Semantic dementia

People with semantic dementia gradually find it harder to remember the meaning of words. For example, they may:

  • Have trouble using the right word – often saying another word or using a vague term like ‘thing’. This may start with names and other words they don’t use very often. As time passes, people will also struggle with more common words and often ask what words mean.
  • Forget what everyday objects are for or find it hard to recognise them.
  • Talk about things at great length and in a vague or roundabout manner.
  • Find it hard to understand what other people are saying.
  • Have problems reading and spelling.

In the later stages, people tend to say less. Changes in behaviour and personality are more common in semantic dementia than the other types of PPA. For example, people may develop obsessions or a sweet tooth, or act in ways that may seem strange to others.

Later they may find it difficult to recognise people they know, things around the house or familiar sounds. This makes it harder to get on with day-to-day life.

Progressive non-fluent aphasia

This condition affects how a person produces speech. For example, they may:

  • Have trouble producing words, although they know what they want to say. Speaking may take a lot of effort and words may not come out right.
  • Find that words come out in the wrong order or are missed out altogether.
  • Stutter or speak more slowly or hesitantly and be hard to understand.
  • Struggle to use the right grammar when speaking or writing letters or emails.

If you use sentences that are long and complex, someone with this form of dementia may find it hard to understand you. Over time, they may develop other symptoms including:

  • Problems with reading, writing and spelling.
  • Difficulty hearing.
  • Trouble understanding some words.
  • Changes in behaviour.
  • Trouble with swallowing.
  • Finding it harder to make decisions or plans.

Some people show signs similar to Parkinson’s disease such as shaking, being unsteady on their feet or having trouble using their hands. It’s also common for people to feel frustrated and low in mood.

Logopenic aphasia

This form of PPA was identified more recently. People with logopenic aphasia are generally able to speak and understand others but have trouble finding the words they want to use. For example, they may:

  • Have trouble remembering the right word. The person may pause as they try to find the word they want.
  • Speak more slowly and hesitantly, and find it hard to say words correctly.

As time passes, people can have more problems with their memory and thinking. For example, someone may forget conversations or appointments, become lost, find it hard to work out how much change they need for a bus fare or struggle to use household appliances, like washing machines.

Someone with PCA may show symptoms of more than one type of PPA at the same time, or as their condition progresses.

With all three types of PPA, problems get worse over time. It becomes harder for people to say what they need and move about on their own.

Dementia is different for everyone who has it, and the speed of change can vary widely. However, someone with PPA will need increasing care and support until the end of their life.

What is Primary progressive aphasia?

Information in this booklet is for anyone who wants to know more about primary progressive aphasia (PPA). This includes people living with PPA, their carers, families and friends.


Order health information

Alzheimer’s Research UK has a wide range of information about dementia. Order booklets or download them from our online form.

This information was written in April 2019 and is due for review in April 2021. Please contact us if you would like a version with references.

Was this information helpful?

Let us know what you think by filling out this short survey.


Dementia Research Infoline

Want to know more about current research? Keen to get involved in research projects?

Contact the Dementia Research Infoline,

9am-5pm, Monday to Friday

0300 111 5 111