Feb 4, 2023 · 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 clear out some viruses. Bacteria Bacteria are single-celled microorganisms. They can live in many different types of environments.

Mar 5, 2024 · Germs live everywhere. There are germs, also called microbes, in the air; on food, plants and animals; and in the soil and water. Germs are on just about every surface, including the human body. Most germs cause no harm. The immune system protects against things that cause infections, called infectious agents. But some germs keep changing to get past the …

Jan 28, 2025 · Overview Flu, also called influenza, is an infection of the nose, throat and lungs, which are part of the respiratory system. The flu is caused by a virus. Influenza viruses are different from the "stomach flu" viruses that cause diarrhea and vomiting. Most people with the flu get better on their own. But sometimes, influenza and its complications can be deadly. To help …

Mar 22, 2025 · Infections caused by bacteria or viruses are usually treated by doctors trained in infectious diseases. Mayo Clinic neurologists and others may work with doctors trained in infectious diseases to evaluate and treat certain infectious diseases.

Apr 8, 2025 · Infectious diseases are illnesses that happen when tiny living beings get inside the body and multiply. 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 they're often harmless or even helpful. But under certain conditions, some organisms can …

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 adenoviruses, astrovirus, cytomegalovirus and viruses that cause hepatitis. Rotavirus is a common cause of sudden childhood diarrhea.

Mar 15, 2024 · Causes Although the exact reason Bell's palsy occurs isn't clear, it's often related to having a viral infection. 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 zoster.

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.

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 spread by: Droplets in the air when someone who is sick coughs, sneezes or talks. Hand-to-hand contact with someone who has a cold.

Jan 18, 2022 · Viral gastroenteritis is an intestinal infection that includes signs and symptoms such as watery diarrhea, stomach cramps, nausea or vomiting, and sometimes fever. The most common way to develop viral gastroenteritis — often called stomach flu — is through contact with an infected person or by consuming contaminated food or water. If you're otherwise healthy, …