Bacterial vs. viral infections: How do they differ? - Mayo Clinic
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 infections In …
Influenza (flu) - Symptoms and causes - Mayo Clinic
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 …
Diarrhea - Symptoms and causes - Mayo Clinic
Jan 18, 2025 · Causes A number of diseases and conditions can cause diarrhea, including: Viruses. Viruses that can cause diarrhea include Norwalk virus, also known as norovirus, enteric …
Medical Diseases & Conditions - Mayo Clinic
Explore comprehensive guides on hundreds of common and rare diseases and conditions from the experts at Mayo Clinic.
Cold and flu viruses: How long can they live outside the body?
Feb 24, 2024 · How long do cold and flu viruses stay alive after people with a virus cough or sneeze? Viruses that cause the common cold, the flu and COVID-19 may be able to infect someone for …
Encephalitis - Symptoms and causes - Mayo Clinic
May 16, 2024 · Encephalitis (en-sef-uh-LIE-tis) is inflammation of the brain. It can be caused by viral or bacterial infections, or by immune cells mistakenly attacking the brain. Viruses that can lead to …
COVID-19 vs. flu: Similarities and differences - 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.
Coronavirus disease 2019 (COVID-19) - Symptoms and causes
Oct 21, 2025 · Coronavirus disease 2019 (COVID-19) is an illness caused by the virus SARS-CoV-2. Learn more about the symptoms, risks and ways to protect yourself.
How well do face masks protect against COVID-19? - Mayo Clinic
Oct 29, 2025 · Face masks can help slow the spread of coronavirus disease 2019 (COVID-19). Learn about mask types, which masks to use and how to use them.
Bell's palsy - Symptoms and causes - Mayo Clinic
Mar 15, 2024 · Viruses that have been linked to Bell's palsy include viruses that cause: Cold sores and genital herpes, also known as herpes simplex. Chickenpox and shingles, also known as herpes …