Singers have to be concerned with many things in order to keep sounding good. They have to stay well hydrated, for example, so their vocal cords stay plump and moist and avoid damage as they knock together. A condition that some singers face is a hiatal hernia (protrusion of the stomach upward into the chest cavity). Although the condition isn't necessarily life threatening, it can bring a singing career to a screeching halt if not properly treated.
How Singing Works
A generation of music educators misrepresented the physiology of singing by saying that a person sings "from the diaphragm." This is incorrect, as the diaphragm is not what controls intake and outtake of air. What actually happens is that the muscles of the abdomen relax during inhalation. When air rushes into the lungs to neutralize the pressure difference that is created, the intercostal muscles of the ribcage expand, and the inflated lung tissues press down on the diaphragm and abdominal muscles. When a singer exhales, the abdominal muscles engage naturally, pushing the diaphragm up and the air out of the lungs. Good singers try to let the the abdominal muscles relax fully upon inhalation so the intercostal muscles can come out as much as possible and so that more air can be taken into the lungs. The diaphragm actually does very little to help singing.
What a Hiatal Hernia Is
In every person's body, the esophogus (the food tube) goes through the diaphragm. Normally, the majority of the stomach is below this point. In a hiatal hernia, however, a portion of the stomach is pushed up and over onto the wrong side of the diaphragm.
Hiatal Hernias and Singing
Because singers do not truly use the diaphragm to sing, some singers with mild hiatal hernias do not even know they have one. However, hiatal hernias can cause problems with pain and acid reflux. Singing thus can be painful as the tissues around the hernia are compressed by the movements associated with inhalation and exhalation. Acid reflux can damage the vocal cords if it is bad and consistent enough. Excessive pressure around the hernia (singers work the muscles and tissues of the lungs, ribcage, and abdomen hard) may aggravate the hernia and cause it to worsen in some cases, although in mild cases singing actually may strengthen the diaphragm tissue enough to stabilize the hernia. One famous singer who has experienced these symptoms due to a hiatal hernia is Chester Bennington of Linkin Park, who has had to cancel gigs. Thus, even though singing with a hiatal hernia may be possible, it isn't advisable.
Most hiatal hernias are very mild and don't require any treatment except that which is used to treat acid reflux. If the hiatal hernia is large, however, then surgery may be needed to correct the problem. Surgery basically involves pushing the portion of stomach that has been pushed up above the diagram back into position and then closing the hernia.
The most common symptoms of hiatal hernias include acid reflux, discomfort, and nausea or vomiting. Singers can manage these symptoms with medication, diet modification, and remaining in an upright position after eating.