What is a common symptom of lactose intolerance?

A common symptom of lactose intolerance is nausea, which occurs as a result of the body's inability to properly digest lactose, the sugar found in milk and dairy products. When individuals with lactose intolerance consume dairy, the undigested lactose ferments in the gut, leading to various gastrointestinal symptoms, including nausea, cramping, bloating, diarrhea, and gas.

The body lacks sufficient amounts of lactase, the enzyme responsible for breaking down lactose. This enzyme deficiency means that lactose passes undigested through the gut, triggering discomfort and symptoms like nausea shortly after consumption of dairy products. Understanding the physiological response that accompanies lactose intolerance helps clarify why nausea is a prevalent complaint among those affected by this condition.