Stuttering refers to a speech disorder that interrupts the flow of speech. People who stutter can experience the following types of disruption:

• Repetitions occur when people involuntarily repeat sounds, vowels, or words.

• Blocks happen when people know what they want to say but have difficulty making the necessary speech sounds. Blocks may cause someone to feel as though their words are stuck.

• Prolongations refer to the stretching or drawing out of particular sounds or words.

The symptoms of stuttering can vary depending on the situation. Stress, excitement, or frustration can cause stuttering to become more severe. Some people may also find that certain words or sounds can make a stutter more pronounced.

Stuttering can cause both behavioral and physical symptoms that occur at the same time. These can include:

• Tension in the face and shoulders

• Rapid blinking

• Lip tremors

• Clenched fists

• Sudden head movements