The Causes of Disease in Humans

829 Words4 Pages
Causes of Diseases in Humans Lifestyle choices greatly affect the risk of disease in human beings. A major disease in humans is cancer, and lung cancer is the most common form of cancer seen in humans. Smoking is the largest cause of lung cancer worldwide, and causes the uncontrolled replication of body cells which is known as cancer. Cancer results when a cell that is not growing suddenly decides to grow out of control and form a tumour. The way in which cancer kills can be very different, depending on what is affected. The most lethal cancers are those that are metastatic, where new tumours are formed and prevent vital organs from functioning properly. Other lung diseases in humans are directly linked to smoking. Smoking is also the major cause of emphysema, a lung disease in humans that reduces a person’s breathing capacity. This is causes when the process of smoking causes the sacs of the alveoli to be destroyed, causing a reduced number of alveoli, and scarring to occur on the walls of the lungs. This decreases the surface area of the alveoli, so reduced the amount of oxygen which can diffuse into the blood. If the disease worsens, then a person may struggle to get sufficient oxygen into the blood even at rest, and die from a lack of oxygen reaching the heart, causing the cardiac muscle to die. Heart disease is the largest cause of death in the United Kingdom, with many different forms of heart disease being causes by lifestyle choices. Coronary heart disease is a disease which affects the coronary arteries, which are essential for providing the cardiac muscle with the oxygen and glucose necessary for respiration. Atheroma is a fatty deposit which builds up in the wall of the arteries, which is made up of cholesterol, dead muscle cells and fibres. A build-up of this deposit reduces the size of the lumen of the artery, lowering the rate of blood flow

More about The Causes of Disease in Humans

Open Document