It takes a certain kind of musical group to inspire someone enough to scream so loudly, it causes physical damage to their person - but that's exactly what happened to one fan, or Directioner as they're sometimes called.
According to a report filed by Dr. J. Mack Slaughter, Jr. (what a name) in the Journal Of Emergency Medicine, a young woman was treated in the Children's Medical Centre in Dallas for symptoms that included a high breathing rate of over 22 times in a minute, and crepitus, which Dr. Slaughter describes as "a crunchy sound - like the sound Rice Krispies make - when you press on certain parts of the body."
Upon further examination, Dr. Slaughter found that the patient had a tear in her lung that caused air to leak into the area between the lung and the chest wall, into the chest cavity itself, and behind the pharynx. In most cases, a tear like this is usually caused either by a sudden change in air pressure, an asthma attack, or lifting of a heavy weight - but almost never screaming or shouting.
Only two other cases were reported where screaming caused a tear in the lung - one was an opera singer, the other was a Marine drill instructor. Just think about that for a second - a One Directioner was able to scream as loud as an opera singer AND a Marine drill instructor. Incredible stuff, really.
Thankfully, the young woman was sent home shortly after being presented as tears in the lung normally heal themselves and, as Dr. Slaughter tells it, he never saw the young woman again. "I told her she'd be famous and get to go on the Jimmy Fallon show and meet One Direction but she was too embarrassed."
Via Journal of Emergency Medicine