Nov 25, 2025 · Viruses that become resistant to antivirals have affected treatment, including for genital herpes, HIV and, in 2008, for influenza (flu). Treating and preventing bacterial and viral …

Mar 5, 2024 · Viruses are responsible for causing many diseases, including: Common cold. Influenza. Measles. Chickenpox and shingles. Coronavirus disease 2019, also called COVID …

Apr 8, 2025 · Bacteria, viruses, fungi and parasites are examples of organisms that can cause illness. Many organisms live in and on our bodies. They're too small to see with the eyes. And …

Apr 30, 2025 · Viral gastroenteritis is an intestinal infection that includes signs and symptoms such as watery diarrhea, stomach cramps, nausea or vomiting, and sometimes fever. The …

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

Oct 22, 2025 · Coronavirus disease 2019 (COVID-19) and seasonal flu have many similarities and differences. Find out what to know and how to protect yourself from these diseases.

2 days ago · 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 …

May 24, 2023 · Causes Many viruses can cause a common cold. Rhinoviruses are the most common cause. A cold virus enters the body through the mouth, eyes or nose. The virus can …

Apr 25, 2025 · Swollen lymph nodes usually occur as a result of infection from bacteria or viruses. Rarely, swollen lymph nodes are caused by cancer. Your lymph nodes, also called lymph …

Apr 30, 2025 · Viruses are the most common causes of colds, in particular viruses called rhinoviruses. There are more than 100 strains of rhinoviruses, and they are very good at …