Viral infection is the invasion of the body by a small agent known as a virus. Viruses replicate inside host cells and can produce toxins that cause disease. The immune system helps to destroy ...

This immune reaction causes symptoms like sneezing, itchy eyes, and a runny nose, but it doesn’t involve an infection. A sinus infection, however, is usually caused by bacteria or viruses. When these ...

While home remedies can be effective, it’s important to confirm that you have a yeast infection—as opposed to a bacterial infection, urinary tract infection, or sexually transmitted infection—before ...