1.5: Public Health and Personal Health

Similar to the distinction between public health and medicine, there is also an important distinction between public health and personal health.

Personal health and wellness is an approach that centers the individual and the different actions a person can take to improve their health and the health of their family. The emphasis is on personal responsibility for health.

Public health, as we have noted, focuses on population health and those actions that are most likely to improve the health of many or all people. The emphasis is on looking out for one another's health across the community.

Both types of actions can play a vital role in prevention, and both forms of responsibility are important values in the United States. Most of the health advice we come across day-to-day focuses on personal health -- eat better, move more, wear a seatbelt. Public health often plays a role in the background to make those healthy choices more possible -- for example, inspecting restaurants and meatpacking plants to ensure that food is safe to eat, promoting farmers markets and SNAP benefits, building sidewalks and parks, monitoring the air for contaminants, and establishing safety standards for cars.

Here are some examples of personal health activities and community and public health activities.

Personal health activities:

• Choosing salad instead of french fries.
• Increasing the variety in one's diet.
• Going for a walk.
• Dancing with friends.
• Playing a sport or going to the gym.
• Getting enough sleep.
• Practicing meditation or some other means of reducing stress.
• Reading a book aloud to a child.
• Brushing and flossing one's teeth.
• Selecting one's preferred form of contraception.

Community and public health activities:

• Health fair.
• Monitoring the rates of disease (like in a measles outbreak).
• Installing speed bumps to slow traffic.
• Community gardens and farmers markets.
• Drop-in hypertension clinic to expand access to screening and care.
• Safer sex outreach events.
• Supporting corner stores to offer more fresh food.
• Billboards and other advertisements about the dangers of vaping.
• Banning smoking indoors in public places.

Note: In this book, we often talk about community health and public health interchangeably -- expanding opportunities for health to a larger population. "Community health" emphasizes the community aspect, like offering health services in a certain neighborhood, or developing activities for a specific community within the larger population. At the local level, public health agencies and community health services usually work closely together.

The scale of change matters

In public health, we sometimes say that there's a difference between what determines the health of individuals versus the health of populations. For example, if we remove soda from vending machines in schools, that alone isn't going to make an individual healthy -- the impact of skipping or delaying drinking a soda at school is relatively small for the individual. However, if the vending machine change leads to students overall drinking 15% less soda per year, that can have a big effect on rates of metabolic disorders like diabetes in the population.

Sometimes a small change at the population level has a large effect, even if it doesn't sound like much when you see it through the lens of personal health. If in a population, average blood pressure goes up by 10 points, that means an increase in thousands of cases of hypertension -- even though for any individual, their blood pressure reading can change vary day to day. A small change that affects a lot of people (population health) can be quite important.

It's similar to the difference between weather and climate. If the weather shifts and the temperature in San Francisco goes up 3 degrees Celsius (about 5 or 6 degrees Farenheit), that just means the fog burned off -- it doesn't mean much at all. But if the climate changes, and the average temperature on Planet Earth goes up 3 degrees Celsius, that's HUGE-- entire nations could be under water, droughts and wildfires would be widespread, and tropical fruit might grow in Canada.