Causes

Experts have not identified a single cause of Crohn’s disease. It may involve a mix of genetic and environmental factors.

Is it genetic?

Researchers have identified more than 100 genes that may increase the risk of developing the disease.

Children with Crohn’s are more likely to have mutations in the genes NOD2 and CARD15. Preliminary research suggests that these genes may cause the disease to appear at a younger age.

Environmental factors

Interactions between environmental factors, infections, and genetic factors may lead to Crohn’s. For instance, exposure to certain infections or environments may activate or change genes in ways that increase the risk of Crohn’s.

Some possible causes and risk factors include:

• Infections: Certain viruses and types of bacteria can damage the intestines, increasing the risk of Crohn’s disease.
• Intestinal bacteria: People with Crohn’s have less diverse populations of intestinal bacteria. Doctors do not know if this causes Crohn’s, or if Crohn’s affects this diversity.
• Race or ethnicity: In the United States, white people are most likely to be diagnosed with Crohn’s, and the diagnosis is rare in people of Asian or Hispanic descent. It is currently unclear whether this is a result of racial bias or a medical factor.
• Geographic location: Some research shows that industrializing areas of Asia and Africa are seeing increases in cases of Crohn’s disease.