Most causes of slurred speech are life-threatening, but there’s also a small number of benign causes.

What would make slurred speech an alarming symptom is if it were new and sudden in onset, as opposed to something that an individual had been living with for a long time due to an already-diagnosed condition such as a previous stroke.

Slurred speech is known in the medical world as dysarthria.

Here are causes that would fall under the category of benign or non-life-threatening.

Cerebral Palsy

This disorder involves muscle control, originating from the brain. It is not a progressive disease.

The part of the brain that controls motor function is impaired.

CP is almost always diagnosed by very early childhood.

You don’t suddenly get cerebral palsy as an adult. It’s commonly caused by brain injury at birth (lack of oxygen).

Bell’s Palsy

One side of the face suddenly develops any of the following symptoms:

• Weakness or paralysis
• Numbness
• Drooling
• Excessive eye tearing
• Inability to taste
• Pain in or behind an ear
• Increased sound sensitivity
• Slurred speech

Bell’s palsy usually resolves on its own after a few weeks, and it’s believed to be caused by an inflammation of the nerves that control these facial-connected functions.

It’s not a progressive disease, though the symptoms can be very troublesome.

A small percentage of patients are left with permanent weakness, paralysis or some other issue with the side of their face that was affected.

Though this negative outcome may not seem benign or harmless, Bell’s palsy is 1) Never life-threatening, and 2) Quite innocuous when compared to the majority of causes of slurred speech.

The thing about Bell’s palsy is that the symptoms strike suddenly and can mimic those of a stroke.

Alcohol Intoxication

In most cases, this is not life-threatening, but it has the potential to cut a life short.

• Behavior resulting from drunkenness that causes a fatal accident.
• Mixing liquor with certain drugs can be fatal or cause permanent coma.
• Alcohol poisoning, without other drugs, can still be fatal.

In addition, poorly fitting dentures can cause a slur in one’s speech.

But more notoriously, recent dental work can do this.

“Some of the possibly benign reasons for slurred speech are severe migraine, and side effects of tranquilizers, sleeping pills or drug abuse,” says Natasha Fuksina, MD, an internal and integrative medicine specialist who combines traditional, integrative and functional medicine to restore health and function.

Life-Threatening Causes of Slurred Speech

“I would not take lightly any presentation with slurred speech!” says Dr. Fuksina.

“Evolving stroke is the most dangerous possibility if a person is having slurred speech. A call to 9-1-1 is in order in that case!”

Slurred speech from a stroke is sudden in onset. If it returns to normal after a few minutes, this may have been a transient ischemic attack (TIA), which is still a 9-1-1 emergency because it’s a mini-stroke that means a massive stroke may be lurking around the corner.

But other serious conditions can cause sudden or gradual slurred speech.


• Brain injury or bleed

• Brain tumor

• Guillain-Barre syndrome

• Huntington’s disease

• Lyme disease

• Multiple sclerosis

• Muscular dystrophy

• Myasthenia gravis

• Parkinson’s disease

• Wilson’s disease

Sudden-onset slurred speech, without any intake of alcohol, narcotics or sedatives, is highly suspect for a stroke or transient ischemic attack.

Also realize that an overdose of prescription drugs (which requires immediate medical treatment) can cause dysarthria!

Gradual development of slurred speech is highly suggestive of a neurological disorder.

In general, slurred speech does NOT mean a harmless or benign condition, and should always be brought to the attention of a medical doctor as soon as possible.

Dr. Fuksina is the founder of astraMDhealth, which includes telemedicine. Double board certified in internal and obesity medicine, she focuses on a personalized approach, including metabolism and genetic makeup, to customize treatments and preventive care.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.  
Top image: Shutterstock/antoniodiaz