The guide

What actually kills people, decade by decade?

By GyroscopeUpdated November 15, 202616 sources

Heart disease and cancer killed about 1.3 million Americans in 2024, more than the next eight causes put together. The order changes with age. From 25 to 44, accidents come first. From 45 to 64 it’s cancer, then heart disease. From 65 on, heart disease leads, with cancer, stroke, lung disease and Alzheimer’s behind it.

Most of us worry about the causes we hear about. The list is mostly slow diseases that build for 20 or 30 years before anyone notices, which is good news in one way, since the same few habits push back on most of them.

What were the leading causes of death in 2024?

Suicide replaced COVID-19 as the tenth cause in 2024. If you’re thinking about suicide, call or text 988, the Suicide and Crisis Lifeline, any time.

How does it change decade by decade?

The CDC’s breakdown by age comes out later than the main list, so these are for 2023, the newest year with ages. Each share is the part of all deaths in that age group.

What moves each age group most:

• 25 to 44. Safety on the road, drugs and alcohol, and getting help early.
• 45 to 64. Not smoking, getting fit, and blood pressure.
• 65 and over. Blood pressure, fitness, strength and balance.
• 85 and over. Strength, balance and walking.

Accidents in the national figures mostly aren’t car crashes. Accidental poisoning, which includes drug overdoses, has been the leading way Americans die from injuries since 2011. In 2022, poisonings killed 112,728 people, falls 47,984 and traffic crashes 44,534.

What are the biggest preventable risks?

Causes of death are what goes on the certificate. Risks are what led there, and they’re where prevention starts. In 2009, a Harvard team worked out how many US deaths in 2005 could be tied to each of a dozen risks you can change. Smoking came first, at 467,000, and high blood pressure close behind at 395,000. Then overweight, not moving enough and high blood sugar, at around 200,000 each.

The numbers overlap, since one death can count under several risks (a smoker with high blood pressure, say), so they’re never added up. The order still holds in newer work. In the Global Burden of Disease study of 2021, the top risks behind US deaths were high blood pressure, high blood sugar, tobacco, diet and a high BMI, in that order. Each bar above links to the guide that covers what lowers it.

A picture from daily life

Think of a long hike. In the first miles the danger is crossing the road to the trailhead. In the middle it’s the long climb, where your heart and lungs do the work. Near the end it’s the loose rocks on the way down, where one slip can end the trip. The hazards change as you go, and so does what keeps you safe.

Which habit moves which cause?

• Blood pressure, for heart disease and stroke. In a million adults, each 20 points (mmHg) higher systolic (the top number) at 40 to 69 went with more than twice the death rate from stroke and twice the rate from coronary heart disease, all the way down to 115/75. Know your number.
• Fitness, for heart disease. In 122,007 treadmill tests, being in the bottom quarter for fitness carried as much risk as smoking or diabetes, or more.
• Not smoking, for cancer and lung disease. Most of the extra deaths among US smokers came from cancers, blood vessel and lung diseases that smoking can cause. Smokers lost more than 10 years. What quitting gives back.
• Moving and lifting, for Alzheimer’s. In 147,374 US adults, 90 to 119 minutes a week of strength training went with a 27% lower death rate from diseases of the brain and nerves. In a 2025 review of step studies, the risk of dementia fell with more steps, with most of the drop by 5,000 to 7,000 a day.
• Balance and leg strength, for falls. More than 1 in 4 older Americans fall each year. People aged 51 to 75 who couldn’t stand on one leg for 10 seconds had an 84% higher risk of dying over 7 years. How do you keep your healthy years?

How much of this is preventable?

It’s more than most people guess. In the Harvard study of 123,219 health professionals, the researchers worked out how many deaths were tied to not having five habits (not smoking, a healthy weight, 30 minutes a day of activity, a good diet and moderate drinking). If the links were causal, missing them accounted for 60.7% of all deaths, 71.7% of deaths from heart and blood vessel disease, and 51.7% of cancer deaths.

These were nurses and other health professionals, so the shares could be different in other groups. And if part of the link comes from healthy people doing healthy things, the true shares are smaller.

Don’t you have to die of something?

Your turn

See your own estimate, with the habit costing you the most years, or look up how long people your age live.