Causes of disease in humans
A disease is a malfunction of the body and or mind and has adverse affects to good health, something that affects the body in a negative way.
Pathogens are microorganisms that cause disease. Examples of this are viruses, bacteria and fungi. To classify as a pathogen the microorganism must; gain entry to the host, colonies the tissues of the host, resist the defenses of the host and cause damage to the host tissues. An infection may occur and symptoms of disease maybe shown by the host. Disease can be transmitted between hosts through different was depending on the pathogen. The most easily accessed way of transmission is through the gaseous exchange system and the digestive system, as these are the systems that co-ordinate with the external environment, where the defenses of preventing infection are lower. Skin covers our body’s surface to prevent infection, however when it is broken its defenses are beached by pathogens. Mucus layers cover the exchange places and acts as a barrier that is difficult to penetrate. Enzymes that break down pathogens and stomach acid kill microorganisms. Pathogens harm in two main ways; damage to host tissues and production of toxins. The damage can occur through the huge population of pathogens and it can inhibit the cells from functioning. Many break down the membranes of host cells causing them to rupture and release the replicated pathogens into the body so they can enter yet more cells and continue to replicate. Most bacterial pathogens produce toxins. The amount of damage caused by a pathogen is related to its rate of division, the faster it multiplies the more damage it causes.
Life style choices can have a serious affect on our immunity to disease, ways of preventing and also increasing the risk of getting diseases. We have the ability to change our exposure to some diseases through our choices. For example there is a correlation between smoking and emphysema. You are at a greater risk of getting emphysema if you are a smoker. There is only a correlation and not a cause as other factors like excessive alcohol consumption; diet, lack of exercise, etc. contribute to this development. You can actively reduce the risk of developing these by; not smoking, preventing becoming overweight, regular exercise, low salt/alcohol/saturated fats diet and increase of anti oxidants in diet. These factors can lead to obesity, and that increases your chances of developing Type II diabetes, which can be both inherited and developed through lifestyle choices. Sufferers are mostly people of aged 40+ although recently adolescents have started developing it due to an increase in childhood obesity. 25% of diabetics have Type I is inherited from the parents that both have either dominant or recessive alleles for the disease. It can be prevented to an extent through maintaining a healthy lifestyle and eating a balanced diet high in fiber, regular exercise. Diabetics cannot hydrolyze carbohydrates into glucose so they have high blood sugar levels to