Nov 25, 2025 · Bacteria cause bacterial infections. Viruses cause viral infections. Antibiotic medicines kill or keep many bacteria from growing but don't treat viruses. Antiviral medicines help the body …

Mar 5, 2024 · Learn how to protect against bacteria, viruses and infections.

Apr 8, 2025 · Infectious diseases can be caused by: Bacteria. These one-cell organisms are responsible for illnesses such as strep throat, urinary tract infections and tuberculosis. Viruses. These …

Apr 8, 2025 · Viruses, bacteria, fungi and parasites all can cause infections. Find out more about how to prevent and treat these conditions.

Jul 17, 2024 · The two types of mosquitoes that most often spread the dengue viruses are common both in and around human lodgings. When a mosquito bites a person infected with a dengue virus, the …

Jul 4, 2024 · How do different types of flu get named and what do those names mean? Flu, also called influenza, is a viral infection of the nose, throat and lungs, which are part of the respiratory system. …

Dec 19, 2025 · Influenza viruses are constantly changing, with new strains appearing often. A person's first flu infection gives some long-term protection against similar strains of flu. But the vaccines …

Explore comprehensive guides on hundreds of common and rare diseases and conditions from the experts at Mayo Clinic.

Nov 12, 2024 · The viruses that cause viral hemorrhagic fevers live in many animal hosts. Most often, the hosts include mosquitoes, ticks, rodents, nonhuman primates or bats. How is it transmitted? …

Dec 9, 2025 · A virus causes most types of hepatitis. Two of the most common ones are hepatitis B (HBV) and hepatitis C (HCV). Both HBV and HCV can make you sick and hurt your liver over time. …