Fast death vs slow death: why most of us now die slowly, and why that’s good news

Fast death: how people used to die

In 1900, U.S. life expectancy was about 47 years. Pneumonia and flu, tuberculosis, diarrheal infections, and diphtheria caused about a third of all deaths. Children under five made up about 30% of deaths.

These were fast deaths: an infection, injury, or childbirth could kill a healthy person within days or weeks. Clean water, sanitation, vaccines, antibiotics, and safer food did more than hospitals to reduce them.

Slow death: how most people die now

The World Health Organization estimates that chronic noncommunicable diseases (long-term, non-contagious illnesses) cause about three in four deaths worldwide. In the U.S., heart disease and cancer lead, and most other top causes, like stroke, Alzheimer’s, and diabetes, are also chronic.

These slow deaths fall into four groups:

• Heart and blood vessel disease: heart attacks, strokes, heart failure
• Cancer
• Brain disease: Alzheimer’s and other dementias, Parkinson’s
• Metabolic disease: insulin resistance, type 2 diabetes, fatty liver, which raise the risk of the other three

A heart attack can feel sudden, but the heart disease behind it usually builds for decades.

Slow diseases start decades before diagnosis

• Heart disease starts in your teens. In a U.S. study of nearly 3,000 people aged 15 to 34 who died of causes like accidents, all the 15- to 19-year-olds had early fatty lesions in the aorta (the body’s main artery). About half had them in a coronary artery.
• Diabetes shows up in blood tests years early. In Britain’s Whitehall II study, people who later developed type 2 diabetes had blood sugar and insulin sensitivity changes years before diagnosis.
• Alzheimer’s starts long before memory loss. In people with an inherited form, brain changes appeared up to 20 to 25 years before expected symptoms.
• Many cancers grow for years, so screening tests like colonoscopies and mammograms can find cancer or pre-cancer while it’s small and treatable.

Slow diseases give you time to prevent them

A disease that takes 20 years to develop gives you 20 years to push back. Most medicine starts treatment at diagnosis, when blood sugar crosses a threshold or plaque blocks an artery.

Prevention works in the years before. The 2024 Lancet Commission on dementia estimated that nearly half of dementia cases worldwide are linked to 14 changeable risk factors, like high blood pressure, inactivity, smoking, hearing loss, and social isolation. Heart disease and type 2 diabetes are even more strongly tied to changeable factors.

Researcher James Fries called the goal compression of morbidity: delaying illness as late in life as possible, so more years are healthy and the final decline is short.

The same habits slow all four

• Heart and blood vessels: don’t smoke, keep blood pressure in range, know your LDL or ApoB (blood tests for artery-clogging cholesterol particles), move daily, and sleep well.
• Metabolism: move regularly (especially after meals), strength train, eat fiber-rich whole foods, sleep enough, and watch your waist size and HbA1c (average blood sugar over the past few months).
• Cancer: don’t smoke, limit alcohol, stay active, avoid sunburn, and get recommended screenings.
• Brain: exercise, control blood pressure, treat hearing loss, sleep well, stay socially connected, and manage depression.

Exercise appears in every group and is the strongest single tool for adding healthy years.

Fast deaths still matter

In the U.S., accidents are the leading cause of death for people aged 1 to 44, and falls are the leading cause of injury death after 65. Many are preventable:

• Driving: wear a seatbelt, keep your phone away, and never drive impaired.
• Home: keep smoke and carbon monoxide detectors working, and lock up medications and other hazards.
• Falls: strength and balance training prevents them best.
• Mental health crises: overdose and suicide are fast deaths too. Reaching out early, to a friend, a clinician, or 988, saves lives.

Psoriasis is linked to slow-disease risk

Chronic inflammation is one thread connecting the slow diseases. Psoriasis is linked to higher rates of heart disease, diabetes, and metabolic syndrome (a cluster of problems like high blood pressure and high blood sugar). If you have psoriasis, ask your clinician to check your blood pressure, blood sugar, and cholesterol regularly, and treat it as a whole-body condition.

Where to start this week

1. Learn your blood pressure, HbA1c, and LDL (or ApoB), and log them each time they’re checked. If you don’t know them, book a check.
2. Ask your clinician which cancer screenings you’re due for. Early heart attacks, diabetes, cancer, or dementia in close relatives may mean starting earlier.
3. Walk 10 minutes after your biggest meal each day. It helps against all four slow diseases.
4. Fix one fast-death risk: test the smoke detector, put your phone away while driving, or add one balance exercise.

What to track

Track daily movement, sleep, stress (0 to 10), energy, skin, and gut. A short daily check-in makes slow changes easier to see.