The word health literally means ‘being good.’ Health is not a condition of physical, mental or emotional well being in which disease and illness are absent; instead it is an ability to live a healthy lifestyle. There is a large array of medical sciences that are dedicated to the study of health; this includes medical care and medical research.

In general the term “health” encompasses a range of factors such as the body’s ability to fight infections, protect itself from external injury, provide nourishment to its cells and maintain life expectancy. The term has a broader connotation than just physical health and covers a number of areas. When a person is young, it is not always easy to determine whether he or she will become ill or not. However, there are certain facts that help in determining the quality of health and whether or not a person will survive for the rest of his or her life.

People have different health needs; one of these needs may be chronic or acute. Chronic diseases are long-term conditions which need to be treated continuously; for example, arthritis or diabetes. Acute diseases usually require treatment after one attack. An example of an acute condition is heart failure. Other chronic conditions include mental illnesses like schizophrenia or bipolar disorder.

People who develop diseases may not show any signs and symptoms, but they may already be suffering from certain diseases. An example of a health problem that does not manifest itself physically is the condition known as “silent disease.” Silent diseases like cancer do not produce any symptoms and the only thing that doctors can conclude about the patient is the fact that he or she is suffering from some other health problem. Some diseases can be detected only when the body undergoes some type of trauma. In such cases doctors look for any changes in the body such as ulcers or bruises that could indicate the presence of a disease.

For example, if a person has a severe accident that involves serious injury, he or she may need a physical examination and treatment for this injury. However, some physical examinations can also be done by doctors that cannot show any visible injuries. These types of examinations are called imaging tests.

Since the term “health” covers a number of areas including the human body, some health care professionals are known to specialize in a certain area of health care. Examples of such health care professionals are doctors who specialize in infectious diseases, doctors who treat patients with AIDS, physicians who focus on skin conditions, physicians who treat heart disease, and physicians who specialize in certain types of cancers.