10. Homicide

9. Suicide

8. HIV

7. Diabetes

6. Pneumonia and influenza

5. Unintentional injuries

4. Chronic obstructive pulmonary diseases

3. Cerebrovascular diseases

2. Malignant neoplasms

1. Diseases of the heart.

Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity. (WHO, 1948)

The science field which focuses on the protection, preservation, and promotion of the health of communities and populations.

How is this different from other health sciences field?

It focuses on the population instead of the individual. It uses the same methodology and technology as other science fields to diagnose and treat ill-health, but it takes a macro look at many human organisms rather than focusing on one person, one patient.

If you look at the human body (draw picture), the optometrist takes care of the eyes, dentist - teeth, podiatrist - feet, pharmacist - medication, the doctor gives a diagnosis and the nurse takes care of the patient. But does this represent all the possibilities of other variables that could affect the patient's health? No.

1. Genetics

2. Environment

3. Disease

4. Behavior

5. Access to health services

 Public Health has five focuses

1. Biostatistics - uses methodology and theory of statistics to identify and solve problems in the life and health sciences.
2. Community Health Sciences - main interest is how health related behaviors of individuals are influenced by and interact with conditions in the social, cultural, physical, and biological environment to influence health status.
3. Environmental Health Sciences - focuses on the protection of health from biological, chemical and physical hazards in the environment.
4. Epidemiology - is the study of the distribution and determinants of disease and injury in human populations.
5. Health Services - is the study of how the organization and financing of health systems promote, prevent and treat disease.

These are the ways that public health assures conditions in which people can be healthy. I stated that at the beginning that public health is unlike other health professional fields because public health looks at the population at large rather than the individual patient. Let me add that the power of public health is derived not from this difference but from the common thread of community. A person is composed of communities of cells and systems - blood cells, brain cells, muscle cells, skeletal system, organ system, muscular system. A population is composed of these same communities. So at the very basic level, all health care workers are public health workers. This is the power of public health. So as you pursue your field of interest, regardless if it is medicine or optometry, pharmacy or nursing, understand that you are seeing a patient static in time and place, a snap-shot, if you will. Understand that there are multi factors invisible in this snap-shot. Learn these factors and take them into consideration in your treatment regimen and you are well on your way to improving public health.

J.P. Donleavy, a writer, wrote, "When you don't have any money, the problem is food. When you have money, it's sex. When you have both, it's health. If everything is simply jake then you're frightened of death".

For most of Western civilization, we are up to the state of being frightened of death, although there are visible gaps in our own society of vulnerable populations. For the underdeveloped countries and developing countries, the situation is much dire. They are still in the most basic mode of the four F's: feeding, fighting, fleeing and mating.

If there is anything that you take home today, I want you to take home this message. Today, we live in a global society. It is no longer possible to live on your little island or in your little town. The same putrid air over the decomposing bodies in Rwanda reaches us in 3 months. Infectious diseases knows no nationalistic boundaries in this era of supersonic air travel. You are breathing the same air that I exhaled 15 minutes ago, and I yours. We lead a more intertwined lives than you can ever imagine. And thus, we need a new paradigm to assure our health in this new environment.

I invite you seek ways to improve the public's health. I invite you to acquaint yourself with public health.