U2 drummer's uncommon ailment causes discomfort during concerts.

Larry Mullen Jr., the famous drummer of U2, has a condition that hinders his ability to play music.

In a new interview with Times Radio, Mullen, the drummer and founding member of the Irish rock band, disclosed that he has dyscalculia, a learning disorder.

"He admitted that he has always been aware of his difficulty in dealing with numbers, explaining that he is numerically challenged and has recently been diagnosed with dyscalculia, a subtype of dyslexia, which affects his ability to count and add."

"Pained" is how Mullen described how the diagnosis affects the way he plays music, according to him.

He revealed, "People often remark that I seem to be in pain while playing. The reason is that I'm counting the bars, which is like climbing Everest. I had to develop strategies to accomplish this task."

According to the Cleveland Clinic, dyscalculia is a learning disorder that impairs a person's ability to comprehend numerical information and mathematical operations. Individuals with dyscalculia face difficulties in understanding and applying mathematical concepts due to the unique way their brains process this information.

While symptoms typically begin appearing in childhood, it often goes undiagnosed.

People with dyscalculia may experience mental health issues, including anxiety and depression, when dealing with math problems, according to the Cleveland Clinic.

Both dyscalculia and dyslexia are specific learning disorders as per the DSM-5, with dyscalculia affecting a person's mathematical skills and dyslexia affecting their reading abilities.

Mullen is discussing his diagnosis while promoting a new documentary, "Left Behind." The film's website describes it as an inspiring story of a group of determined moms who founded the first public dyslexic school in the largest school district in America, New York City.

The drummer, who wrote and produced the music for the movie that premiered at the Woodstock Film Festival in October, has disclosed that his son has dyslexia.

In 1976, at the age of 14, Mullen initiated U2 by posting a note on a bulletin board at Mount Temple School in Dublin that read, "Drummer seeks musicians to form band."

The band members, including Adam Clayton, David Evans (The Edge), and Paul Hewson (Bono), auditioned in the kitchen of their home. Despite disagreements over the years, they have remained together as a band.