Hypogammaglobulinemia is a problem with the immune system that prevents it from making enough antibodies called immunoglobulins. Antibodies are proteins that help your body recognize and fight off foreign invaders like bacteria, viruses, and fungi...

Secondhand smoke is the combination of smoke from the burning end of a cigarette and the smoke exhaled by the smoker. It is dangerous to both smokers and nonsmokers. Secondhand smoke contains more than 7000 chemicals, including 70 that can cause c...