Only recently has evidence emerged showing the importance of inherited factors in determining our risk of developing disease. We take for granted the fact that children resemble their parents and other relatives and that families typically share physical and behavioural characteristics. It is this shared biological inheritance that also accounts for certain diseases “running in families”.
Many of our physical and behavioural characteristics are determined by our genes. An explanation of the structure and function of genes and how they are inherited is given elsewhere (see Genes and inheritance).
Genetic factors, along with lifestyle factors, contribute to many common diseases. The genes that you inherit from your parents help to explain why susceptibility to certain diseases varies from one family to the next, although only a few rare disorders are directly caused by altered genes.
By collecting information on your family’s medical history, you may be able to identify diseases that appear to be particularly common in your family. This type of information can provide a valuable early indication of genetic tendencies to particular diseases.
The range of genetic tests used to determine whether either partner in a couple has inherited specific altered genes is increasing all the time. Geneticists can assess the risk of the couple’s children inheriting the altered genes and give advice on the likely effects on their health. In many cases, this allows the symptoms of a genetic disorder to be treated early or relieved effectively.
Until the mid-20th century, people consulted a doctor only when they were ill, injured, or pregnant. Although for many people this is still the case, the intervening period has seen an explosion in public knowledge about health and disease and a growing emphasis on health care that prevents as well as treats disease.
The main point of contact with health services for most people is with their GPs or other primary health-care professionals, such as practice nurses, dentists, and opticians. The first article offers advice on choosing a practice and getting the best from consultations with your doctor.
The next subject is immunization. In developed countries, programmes of immunization from birth onwards have dramatically reduced many of the infections that used to be common in childhood. Immunization also protects people from serious illness in later life.
As well as treating disorders, primary health-care providers are responsible for two important elements in preventive health care: checkups carried out during childhood and later in life, and screening tests to identify risk factors and early signs of disease. These topics are covered in the last two articles.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.