A speech disorder can cause one to have the inability to speak properly and clearly. This can be seen through repeated words, stuttering, long pauses, etc. Speech disorders are just one of the various types of communication disorders. Such speech disorders can be caused by a variety of things. This includes stress, nerve damage, conditions with the nervous system, as well as brain damage. The most common disorders include apraxia, dysarthria and aphasia. Apraxia can be seen in childhood as well as adulthood. With childhood apraxia, a child is not able to use their muscles properly to portray a massage. They are not able to move their tongue or mouth in the proper way in order to make certain sounds. This can cause a child to limit how much they can talk. With adult apraxia, it is acquired and can be due to brain damage. Such brain damage can be due to certain conditions such as lack of oxygen to the brain, a brain injury or brain damage. This form of apraxia can leave gaps within their speech. As they once knew how to speak correctly, they may not be able to make it sound right consistently. They can have a hard time controlling their tongue, lips and mouth in order to make the correct sound. Such adults may have to talk slower, and in severe instances, they can no longer be able to talk. Dysarthria can occur from brain damage that results in muscle weakness. They often cannot move their mouth or tongue very well or even at all. They can speak either very slowly or very fast and often slur their words. Their voice can also sound very different due to the brain damage. Aphasia is a linguistic impairment caused by injury to the left hemisphere of the brain. They are shown to have difficulty with speaking and understanding people, as well as writing and reading. They often have hard times remembering words and thus have a hard time forming full sentences.