Dysarthria is a speech disorder. It happens when the muscles needed for speech are damaged or weak.

It is not the same as aphasia , which is a language disorder.

Mouth and Throat
Mouth Throat
Dysarthria may happen due to problems with the muscles needed to speak.
Copyright © Nucleus Medical Media, Inc.


Common causes are:

  • Stroke
  • Brain tumor or traumatic brain injury
  • Infection
  • Conditions that paralyze the face or cause weakness, such as Bell palsy
  • Degenerative brain diseases, such as
    • Alzheimer disease
    • Huntington chorea
    • Parkinson disease
  • Neuromuscular diseases, such as:
    • Amyotrophic lateral sclerosis (ALS)
    • Cerebral palsy
    • Multiple sclerosis
    • Muscular dystrophy
    • Myasthenia gravis
  • Alcohol or substance use disorder
  • Surgery or weakness on the tongue
  • Structural problems, such as not wearing dentures
  • Side effects of medicines that act on the central nervous system

Risk Factors

This problem is more common in older adults. It is also more common in people who have any of the health problems that cause dysarthria.



Problems may be:

  • Speech that sounds:
    • Slurred
    • Hoarse and breathy
    • Slow or fast and mumbling
    • Soft like whispering
    • Strained
    • Nasal
    • Suddenly loud
  • Drooling
  • Trouble chewing and swallowing


The doctor will ask about your symptoms and health history. A physical exam will be done. It will focus on the muscles needed for speech.

Images may be taken of the brain. This can be done with:

  • X-rays
  • MRI scan
  • CT scan
  • PET scan
  • Single-photon emission computed tomography (SPECT) scan

The electrical function of your nerves and muscles may be tested. This can be done with:

  • A nerve conduction study
  • An electromyogram



The cause will need to be treated. Speech therapy will also be needed.


There are no known guidelines to prevent this health problem. Managing chronic health problems may help.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.


American Speech-Language-Hearing Association http://www.asha.org 

National Institute of Neurological Disorders and Stroke http://www.ninds.nih.gov 


Heart and Stroke Foundation http://www.heartandstroke.com 

Speech-Language and Audiology Canada http://sac-oac.ca 


Dysarthria. American Speech-Language-Hearing Association website. Available at: https://www.asha.org/public/speech/disorders/dysarthria. Accessed January 26, 2021.

O'Hare A, Bremner L. Management of developmental speech and language disorders: Part 1. Arch Dis Child. 2016 Mar;101(3):272-277.

Speech and language disorders. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/speech-and-language-disorders. Accessed January 26, 2021.

Stroke symptoms. American Stroke Association website. Available at: http://www.strokeassociation.org/STROKEORG/WarningSigns/Stroke-Warning-Signs-and-Symptoms%5FUCM%5F308528%5FSubHomePage.jsp. Accessed January 26, 2021.