The brain and motor neurons control the movement of muscles in the mouth and throat required for speech production. Neurological damage can cause dysarthria and slurred speech. However, a person can experience slurred speech and not have dysarthria.
Someone with dysarthria may also:
- mumble
- talk too fast
- talk too slow
- have a hoarse or raspy voice
- have a robotic-like sound
- have difficulty moving their tongue, lips, or jaw
- use the wrong words
- have problems understanding others
This article will discuss when to contact a doctor for slurred speech. It will also examine the possible causes, related symptoms, diagnosis, and treatment of slurred speech.
When to see a doctor for slurred speech
Slurred speech can be a symptom of a stroke, drug overdose, brain injury, or another condition. Always seek medical care straightaway for slurred speech.
Call 911 for sudden slurred speech or any of these other stroke symptoms:
- numbness or weakness on one side of the body
- sudden change in vision, loss of vision, or eye pain
- difficulty with memory, thinking, writing, or reading
- severe headache
- change in consciousness or alertness, such as passing out

The American Speech-Language-Hearing Association (ASHA) explains that proper speech requires the brain, mouth, tongue, throat, and breathing muscles. Damage or disease affecting any of these organs could cause slurred speech or dysarthria.
Some people are born with conditions, such as cerebral palsy, that cause slurred speech. Other times, it can develop later in life.
Causes of slurred speech range from temporary to chronic conditions that do not go away. Causes include:
- anxiety
- medications that affect the nervous system
- tooth abscess
- mouth pain
- tongue or gum swelling
- Bell’s palsy
- drug overdose, including alcohol poisoning
- dementia
- cerebral palsy
- hearing impairment at birth
- multiple sclerosis
- muscular dystrophy
- myasthenia gravis
- amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig’s disease)
- Parkinson’s disease
- brain tumor
- transient ischemic attack (mini stroke)
- stroke
- traumatic brain injury
Conditions that affect your ability to speak may cause other symptoms too. These conditions may involve parts of the nervous system that control speech or the speech muscles themselves.
Brain and nerve symptoms
Symptoms involving the brain and nerves can include:
- dizziness
- balance problems, difficulty walking, and falls
- blurred or double vision
- muscle twitching, spasms, or seizures
- reduced ability to write or read
- reduced ability to understand things you used to know
- reduced memory
- headache
- nausea with or without vomiting
- numbness or tingling
Muscle symptoms
Symptoms involving the muscles can include:
- difficulty chewing or swallowing
- drooling
- muscle weakness
To diagnose the cause of slurred speech, a doctor will evaluate your symptoms, take a medical history, and perform a physical exam.
Testing
Tests your doctor may order include:
- a neurological exam, which tests your reflexes, balance, and mental status
- blood and urine tests, which can help identify a toxic substance or infection
- imaging exams, which may include a brain CT scan or MRI
- nervous system studies, such as electroencephalography and electromyography
Questions your doctor may ask
To diagnose the underlying cause of slurred speech, your healthcare professional will ask you several question, which may include:
- How long have you had slurred speech?
- Did your slurred speech develop slowly or suddenly?
- Have you experienced any recent injuries or trauma?
- Do you have any other symptoms?
- What medications are you taking?
Treatment for slurred speech depends on the cause, severity, and how much it impacts your daily life. Some conditions may resolve with time as the tissues in the brain, nerve pathways, or muscles heal. For instance, Bell’s palsy typically subsides in a few weeks.
Medical treatment for other conditions that cause slurred speech, such as Parkinson’s disease, may reduce the effect on speech.
Speech therapy
For slurred speech due to permanent neurological changes, you will likely receive a referral to a speech-language pathologist (SLP). This person will study how you say single words and sentences. They will also evaluate your breathing as you talk. They will develop a therapy and treatment plan that fits your needs. The SLP may focus on:
- slowing your speech
- taking in more air before you speak
- exercises to strengthen the muscles you use in your face and throat to speak
- moving your lips and tongue more to help clarify words
Alternative communication methods
In someone with severe speech difficulties, or dysarthria, the SLP will add on therapy, such as showing you different ways of communicating. This is augmentative and alternative communication. These range from hand gestures to computers:
- gestures
- facial expressions
- writing and drawing
- pointing to or using pictures (particularly useful for young children and people who do not have the motor skills to write)
- touch screen computers
- speech-generating devices
The outlook for a person with slurred speech varies greatly depending on its severity and other factors. Slurred speech from some causes is permanent. In other cases, treating the underlying cause may increase speech clarity.
When slurred speech comes on suddenly, it may be due to a stroke. Fast diagnosis and treatment can help prevent permanent brain damage and loss of function, including dysarthria.
The
- F: face drooping on one side
- A: arm weakness on one side
- S: speech difficulty
- T: time to call 911
Questions people ask about slurred speech include:
When should I be concerned about slurred speech?
Sudden onset of slurred speech is a sign of a stroke and other serious conditions, so it is always a concern.
Does slurred speech always mean a stroke?
No. Other causes include drug intoxication, medication side effects, Bell’s palsy, and Parkinson’s disease, among many other conditions.
Is slurred speech a symptom of anxiety?
Yes, slurred speech is a possible symptom of anxiety and emotional stress.
What neurological disorders cause speech problems?
Dementia, multiple sclerosis, Parkinson’s disease, Bell’s palsy, and brain damage are among the many neurological disorders that can cause speech problems.
Slurred speech is often considered a synonym of the medical term “dysarthria,” but they are not the same thing. Rather, slurred speech is one possible sign of dysarthria.
Temporary and permanent damage to the brain and nerves that control muscle movement, including drug intoxication, stroke, traumatic brain injury, multiple sclerosis, cerebral palsy, and Bell’s palsy, can cause slurred speech.
Treating the underlying cause may resolve slurred speech. An SLP is a specialist who can evaluate your speech, language, and breathing. Speech therapy and alternative communication methods may help a person with dysarthria communicate better. This can help them stay engaged with loved ones and avoid social withdrawal.