What does it mean to be a carrier of an illness?

To be a carrier of an illness means you have the bacteria, virus, or genetic mutation that causes a disease inside your body, but you do not show symptoms of the illness yourself, yet you can still pass it on to other people and make them sick. There are two main types of carriers in medicine. An infectious disease carrier is someone infected with germs like bacteria or viruses who feels healthy but can spread the illness through coughing, touching, or contact, like Typhoid Mary who famously carried typhoid fever without being sick herself. Carriers can be temporary, such as someone who has recovered but still sheds germs, or chronic, carrying germs long term. A genetic carrier is someone who carries one copy of a gene mutation for a recessive condition like cystic fibrosis, sickle cell, or Tay-Sachs, does not have the disease because you need two copies to be sick, but can pass the gene to children, who could get the disease if both parents are carriers. Being a carrier does not mean you are ill, but it means you should take precautions like hand washing, safe practices, or genetic counseling before having children.