Germs and Your Immune System

Germs are tiny living things — bacteria, viruses, and fungi — that can get inside your body and make you feel unwell. They are so small that millions would fit on a full stop. Luckily, your body has a brilliant defence system called the immune system that fights them off day and night.

It helps to know the difference between the two main germs. Bacteria are tiny living cells that can multiply very quickly. Viruses are even simpler and smaller — they are not really alive on their own, so they sneak inside your cells and use them to make copies of themselves.

Your immune system has several layers of protection. Your skin is a wall that keeps most germs out. The mucus lining your nose and throat traps germs like sticky flypaper. If germs do get inside, white blood cells rush to attack them — they are the brave soldiers of your body.