Health can be defined as a person’s physical, mental and social condition. Someone who is healthy feels good physically and has a positive outlook on life is regarded as being healthy. People need good health for growth and development and to maintain a good and healthy life a person would need to have good shelter, nutrients, exercise, sleep, rest and good hygiene to reduce chances of infection. A disease is a disorder of a malfunction of the mind or body which leads to the departure form good health care. It can either be a disorder for a specific tissue or organ from a single cause or it could be many causes, which is described as Multifactorial.
Signs and symptoms that are physical, mental or both are characteristics of disease. Acute disease is disease that has sudden onsets with rapid changes and last for only a short time. What distinguishes between a healthy and an unhealthy person? A person needs health to grow and realise their potential and to play an active roll in society. They can only do this if they live in an environment free form hazards to health. However a person that is considered to be healthy may not have any type of disease but their living conditions, diet or personal behaviour may be putting themselves at risk of developing chronic diseases which only manifest themselves in later life.
Categories of diseases There are nine recognisable categories of diseases although some disease fit into more then one category. Physical disease This is the temporary or permanent damage to the part of the body. It includes all other categories except for mental illness, as there are no signs of physical damage to the brain. An example of physical disease would be leprosy. Infectious disease Organisms that live or on our bodies and gain their nutrients from us are called parasites. If they cause disease then they are Pathogens e.g. viruses, bacteria, fungi, worms and insects. They are communicable and people infected with no symptoms are carriers. Pathogens can be transmitted in different ways like:
Direct contact- sexual intercourse enables the transmission of syphilis bacteria; a persons foot which touches the damp floor of a swimming baths can tranfer the Athelet’s foot fungus. Droplet infection- A sneeze propels tiny droplets of nasal mucus carrying viruses such as those causing influenza. Via a vector- If a person with typhoid bacteria in the gut handles food, the bacteria can be passed to a susceptible person.
Via food or water- Chicken meat kept in warm conditions encourages the reproduction of salmonella bacteria which can be transferd to the human consumer, who has food poisoning as a result. Examples of this type or disease are malaria and measles. Non-Infectious disease All disease that are not cause by pathogens are termed as non-infectious diseases. The following types of diseases are not caused by pathogens; deficiency disease, Inherited disease, Degenerative disease, Mental disorders, Social disease and self-inflicted diseases.
Some non infectious diseases have one cause where as others are more complex and are multifactorial. Deficiency Disease These are nutritional disease caused by inadequate or imbalanced diet. Although most of the worlds population have enough to eat, they do not always eat a balanced diet. One or more of the essential nutrients such as proteins, vitamins and minerals can be missing or in short supply. As a consequence people suffer from deficiency diseases such as: Genes passed on from parents to children cause this. It is caused by dominant or recessive alleles. Some people can show symptoms from birth where as others can develop them later in life.
There is no possible cure for an inherited disease but may eventually become possible with a technique called gene therapy. An example of inherited disease would be cystic fibrosis. This disease results from an abnormality in a channel protein that allows chloride irons to flow out of cells across plasma membranes. Cells with these chloride irons are found in the lungs, pancreas and testes. If the channel does not work properly, it can cause a sticky mucus stopping water and chloride molecules from moving in or out. This makes breathing more dificault and is likely to form a breeding ground for bacteria, resulting in infections. The sufferer must have regular physiotherapy to loosen and get rid of the mucus.