Copy: The immune system is the human bodies first line of defence against disease, and it works day and night to keep the body free from infection and illness. The body is full of microbes and it is only if the immune system becomes weak the body is attacked and we fall sick, however, there are some types of pathogens (organisms that causes disease) that can make you sick just on entering the body. These organisms can enter the body in many ways, such as, through skin contact, airborne elements, or being too close to an infected person, etc. In this article I am going to concentrate on the four most common types of body-invaders which are viruses, bacteria, fungi, and parasites. Viruses: once you are infected the virus keeps reproducing itself, some viruses can stay dormant for a while and although you may appear to have got over your viral infection, the virus can quite easily re-appear again. Many will seek to get antibiotic medication but antibiotics do not kill viruses, so you would need to seek help from your GP. Bacteria: this is a single cell microorganism, there are a huge variety of types and they can live anywhere, including in and on the body. Not all bacteria cause problems or sickness, usually, this only occurs if your immune system has broken down. Meaning if you are already weakened, bacteria can result in any type of bacterial infection. Antibiotics can be used but it is not good for your health to seek antibiotics too often as the body can become resistant, making more dangerous infections difficult to treat. Fungi: It appears that millions of different types of fungi exist and there are only a handful (in comparison) that can cause you to become sick. Fungi is everywhere, and causes infection when they enlarge. Fungi, once the infection has taken hold, because of their structure they are sometimes difficult to kill off. There are some new strains of fungi that are proving to be dangerous, so there is a lot or research going on, (thank goodness). And finally, there are Parasites: Parasites are nasty creatures, living on or in the body whilst feeding off it. Parasitic infections are more common in warm, tropical areas, but of course they can be found anywhere. There are three main types of parasites, that live inside and outside of the body, they include worms, ticks, and mosquitos, they can be picked up and spread in many ways including through food, soil, water, blood and insect bites. So, it’s very important to keep our bodies, inside and out as pure and as clean as possible.