Infectious Diseases

Being diagnosed with an infectious disease can be unsettling and frightening. We understand and are here to provide the expert care you need. As part of Mayo Clinic, we are connected to more than 40 infectious disease physicians, who specialize in identifying and treating infectious diseases.

Infectious diseases are disorders caused by organisms — such as bacteria, viruses, fungi or parasites. Many organisms live in and on our bodies. They're normally harmless or even helpful, but under certain conditions, some organisms may cause disease.

Some infectious diseases can be passed from person to person. Some are transmitted by bites from insects or animals. And others are acquired by ingesting contaminated food or water or being exposed to organisms in the environment.

Signs and symptoms vary depending on the organism causing the infection, but symptoms often include fever and fatigue. Mild infections may respond to rest and home remedies, while some life-threatening infections may require hospitalization.

Many infectious diseases, such as measles and chickenpox, can be prevented by vaccines. Frequent and thorough hand-washing also helps protect you from most infectious diseases. Learn about infectious disease symptoms and causes here.