There are several reasons why an international citizen, visa holder, or permanent resident may be denied citizenship. Some of the most common reasons are:
1. Anyone who is deemed a risk to engage in terrorist or espionage against the United States.
2. Anyone who has committed an aggravated felony (Removal & Deportation Link).
3. Anyone who has a communicable disease such as AIDS, tuberculosis, typhoid fever, and other serious transmittable ailments that could pose a severe health crisis.
4. Individuals who have certain physical or mental disorders. With the exception of those who can prove they have been cured of the condition or have the condition under control.