How can lifestyle, genes and environment affect health?Interactions and disease
Our genomes interact with our environment to create our phenotypes. While some aspects of our environment are beyond our control, scientists are realising that lifestyle interacts with the genome too.
Different types of disease may interact. If having one disease causes another to develop then the second disease is a complicationA second disease that comes as a result of the first. of the first.
Defects in the immune systemThe body's defence system against entry of any foreign body, including pathogens and agents such as pollen grains. The role of the immune system is to prevent disease. mean that an individual is more likely to suffer from infectious diseases. For instance, human immunodeficiency virus (HIV) infections, which lead to AIDS, affect the immune system and lead to an increase in infectious diseases.
virusAn ultramicroscopic infectious non-cellular organism that can replicate inside the cells of living hosts, with negative consequences. living in cells can be the trigger for cancers. For instance, the majority of cases of cancer of the cervixRing of muscle at the lower end of the uterus. are linked with a virus present in the female reproductive systemThe organs and tissues involved in producing offspring.. It is spread by sexual intercourse and is called human papilloma virus (HPV).
The reaction of the immune system to pathogenMicroorganism that causes disease. and other foreign bodies can trigger allergic reactions that lead to skin rashes and asthmaA disease that affects the respiratory system.. For instance, severe respiratory infections in babies can lead to asthma in later childhood.
Severe physical ill health can lead to depressionDepression is a condition which affects mental health and causes people to experience symptoms such as depressed mood, loss of interest or pleasure and feelings of guilt or low self-worth. and other types of mental illness.