Aphasia
Aphasia (also called dysphasia) is a condition that makes it difficult to communicate. It can make it hard to speak, read, write and understand others. It's often caused by a stroke or brain injury. There's no cure, but people usually improve with treatment.
Dysarthia
Dysarthria is where you have difficulty speaking because the muscles you use for speech are weak. It can be caused by conditions that damage your brain or nerves and some medicines. Speech and language therapy can help.