Immune System Archive

Cellulitis, a skin infection that often occurs on the lower leg, develops when bacteria enter the body through a cut, bite, or other wound. A new study shows key aspects of healing typically occur within 10 days of treatment, but symptoms can linger for some time after that.

The human body has hundreds of lymph nodes, one part of the immune system that helps defend the body against health threats. They aren't usually noticeable, but they are always working to deal with potential health problems.

The thymus gland is very important in the development of the immune system during fetal growth, infancy, and early childhood. As we grow into adulthood the thymus shrinks, but growing evidence suggests the gland may play a role in adult health for much longer than previously thought.

Removing tonsils in childhood was once routine care for healthy children, but is no longer recommended. Why are some organs and glands — appendix, tonsils, adenoids and more — considered expendable and why do we have them if they're not needed?

Ads for products that promise to supercharge the body's immune system make claims that sound too good to be true. But do these products actually work? 

News coverage of a case of leprosy in central Florida may have made it seem like there is an increased threat the disease would spread. Misconceptions about this disease have persisted for a long time, but the facts are reassuring.

Not only is our face our calling card to the world, its features evolved to mount immune system defenses, help ward off illness, and protect us in many ways. Our eyes, nose, mouth, and facial structure itself all contribute to our continued well-being.

With influenza virus, a new vaccine must be developed each year to adapt to the virus's changing structure.

Hives are red, itchy welts that crop up on the skin. Allergic reactions and stress, among other triggers, can cause episodes of hives, which typically last several days to a couple of weeks. Cases that last six weeks or longer may be autoimmune hives.

A fever is the immune system's response to an infection or invader. Most fevers drop after people take over-the-counter medications. People should call a doctor if their fever reaches 103° F and go to an emergency room if it reaches 105°.