About
- National Health and Nutrition Examination Survey (NHANES) data have identified health issues and led to health improvements for more than 60 years.
- Thousands of Americans have contributed to these accomplishments by participating in the survey.
- Learn how NHANES data have helped improve the health of Americans.
NHANES improves our health
For more than 60 years, National Health and Nutrition Examination Survey (NHANES) staff have interviewed and examined thousands of Americans for this important survey. Today, teams of interviewers, nurses, dentists, and health technicians head out to communities across the United States for NHANES. Each year, they collect and update important health and nutrition data.
An NHANES interviewer may never have knocked on your door, but our program supports the health of everyone living in the United States. Here are some examples of how we all benefit from NHANES.
Undiagnosed conditions
NHANES measures health risks
NHANES estimates show how common undiagnosed conditions are. For example, about 40% of adults with high blood pressure don't know they have hypertension. NHANES exams and laboratory tests can identify these conditions. Participants may learn they have an undiagnosed condition before it leads to a health crisis.
NHANES data and estimates help government officials, healthcare providers, and others understand how common undiagnosed conditions are. They can use what they learn to take action to detect and treat them.
Undiagnosed diabetes is common
Today, about a quarter of adults with diabetes don't know they have it.
Childhood growth charts
NHANES answers health questions
Parents naturally wonder about how their children are growing. Is he too small for his age? Is it strange that she's taller than the rest of her class? How do my children's measurements compare to everyone else's?
Your doctor can answer your questions about your child's growth because of NHANES. We used data from the body measurements taken during NHANES health exams to develop growth charts for children. You will find these growth charts on the walls of pediatricians' offices across the United States and around the world. Over the years, we have improved and extended the charts, most recently to include children with severe obesity.
Lead-free gasoline
NHANES identifies health problems
In the 1970s, NHANES gave us the first clear evidence that Americans had too much lead in our blood. At the time, adding lead to gasoline was normal practice. But even low levels of lead in blood can cause serious, permanent health problems. The NHANES findings led Congress, the Environmental Protection Agency, and others to take steps to remove lead and paint. The results have been remarkable.
Lead levels dropped
By the 1990s, only 4% of Americans had too much lead in their blood.
High levels of lead remain a problem for some groups. NHANES data and other evidence continue to show that some groups of children have higher levels of lead in their blood. Children are more likely to have high lead levels if their families have low income and live in older houses in cities where lead paint was once commonly used. NHANES helps public health agencies know if lead is still causing harm so they can provide help.
Vitamins and minerals in diet
NHANES shares health information
NHANES data help experts studying which vitamins and minerals we need to eat, drink, or take and how much of each are required for a healthy diet. The U.S. Department of Agriculture (USDA) and the Department of Health and Human Services partner to collect comprehensive nutrition data for the nation through NHANES.
USDA relies on the diet and nutrition information that NHANES gathers to help determine what Americans are eating. And the U.S. Food and Drug Administration (FDA) uses this information to determine how much they should be eating.
Early NHANES surveys showed that low iron levels were a serious problem for many people, including women of childbearing age, preschool children, and the elderly. As a result, the government decided to add iron to grain and cereal—fortifying them to increase the amount of this essential mineral in diets.
Health officials also use NHANES data to monitor blood levels of folate (folic acid) in women of childbearing age. This important vitamin prevents some types of birth defects. FDA requires food manufacturers that sell "enriched" products using wheat, rice, oats, cornmeal, or other cereal grains to add folic acid these foods.