Health statistics: what the data actually shows

What is the average life expectancy?

US life expectancy at birth fell sharply during the COVID-19 pandemic, dropping from 78.8 years in 2019 to 76.4 years in 2021, the lowest level since 1996. The 2022 CDC/NCHS data shows a partial rebound to 77.5 years, but the recovery has not fully closed the pre-pandemic gap. The decline represents one of the largest short-term drops in US life expectancy since World War II.

The gap between men and women is substantial and persistent. In 2022, life expectancy at birth was 74.8 years for men and 80.2 years for women, a difference of 5.4 years. This gap widened during the pandemic, driven partly by higher COVID-19 mortality rates among men and partly by the disproportionate impact of drug overdose deaths on male populations.

Internationally, the United States ranks well below other high-income countries. Japan leads with 84.3 years, and countries including Australia (83.2), Germany (81.1), and the United Kingdom (81.0) all substantially exceed the US figure. Use the life expectancy calculator to see a personalised projection based on your age and health profile, or explore the biological age calculator to understand how lifestyle factors affect your expected lifespan.

How much sleep does the average person get?

Gallup polling data covering more than two decades shows that average self-reported sleep duration among US adults has declined from 7 hours 9 minutes in 2004 to approximately 6 hours 54 minutes today. This places the population average below the American Academy of Sleep Medicine (AASM) recommended range of 7 to 9 hours for adults.

CDC Behavioral Risk Factor Surveillance System (BRFSS) data finds that 35% of US adults regularly report fewer than 7 hours of sleep per night. Chronic short sleep is associated with elevated risk of obesity, cardiovascular disease, diabetes, and impaired immune function. Despite widespread public health messaging, the proportion of adults meeting sleep recommendations has not improved significantly over the past decade.

Sleep duration varies meaningfully by age. Young adults (18 to 24) average closer to 7.5 hours, while middle-aged adults (45 to 54) average approximately 6.5 hours. Adults aged 65 and over often report shorter sleep but with more daytime napping, complicating direct comparisons. Use the sleep debt calculator to see how your current sleep patterns compare against your personal need.

What is a normal resting heart rate?

The American Heart Association (AHA) defines a normal resting heart rate for adults as 60 to 100 beats per minute (bpm). This range reflects the broad variation in the general population. Trained athletes and people with high cardiovascular fitness routinely measure below 60 bpm, a condition called bradycardia, which is clinically normal in fit individuals and not a cause for concern in the absence of symptoms.

Population data from NHANES and large epidemiological studies suggests the actual mean resting heart rate for US adults sits between 72 and 78 bpm, close to the middle of the normal range. Heart rate tends to decline slightly with age in fit individuals as cardiac efficiency improves, but can rise with age in sedentary individuals due to declining cardiovascular health.

A resting heart rate persistently above 100 bpm (tachycardia) warrants clinical evaluation. There is emerging research suggesting that a resting heart rate in the lower half of the normal range (60 to 70 bpm) is associated with lower long-term cardiovascular mortality risk compared to rates in the 80 to 100 bpm range. Use the resting heart rate calculator to compare your own figure, or see the fitness age calculator for broader cardiovascular fitness context.

What is normal blood pressure?

In 2017, the American Heart Association revised its blood pressure classification guidelines, lowering the hypertension threshold from 140/90 mmHg to 130/80 mmHg. This change immediately reclassified approximately 31 million additional Americans as hypertensive, bringing the estimated prevalence of hypertension among US adults to nearly half the population (47%).

Under the 2017 guidelines, blood pressure is classified into four categories: normal (below 120/80), elevated (120 to 129 systolic, below 80 diastolic), Stage 1 hypertension (130 to 139/80 to 89), and Stage 2 hypertension (140 or above / 90 or above). A hypertensive crisis is defined as above 180/120 and requires immediate medical attention. Despite its prevalence, hypertension is often asymptomatic, earning it the description as a silent condition.

Control rates remain poor. Of the approximately 116 million adults with hypertension, only around 24% have their blood pressure adequately controlled through medication or lifestyle modification. Use the blood pressure calculator to see which category your readings fall into and what the population distribution looks like.

What is the average BMI?

CDC NHANES data from the 2017 to 2020 survey cycle shows the mean body mass index (BMI) for US adults is approximately 30.0, which falls exactly at the threshold between the overweight and obese categories. The obesity prevalence among US adults stands at 41.9%, up from 30.5% in 1999 to 2000, a 37% relative increase over two decades.

BMI distribution across the US adult population breaks down as follows: 27.4% are classified as having a healthy or underweight BMI (below 25), 30.7% are classified as overweight (25 to 29.9), and 41.9% are classified as obese (30 or above). Within the obese category, severe obesity (BMI 40 or above) affects approximately 9.2% of adults.

Obesity prevalence varies substantially by demographic. Rates are higher among middle-aged adults (40 to 59) compared to young adults or those over 60. There are also significant differences by race and ethnicity, and by state: obesity rates range from approximately 24% to over 40% depending on geography. Use the healthy weight calculator to see where your own BMI sits in the population distribution, or the body fat percentage calculator for a more nuanced body composition assessment. For those managing their weight with GLP-1 medications, the weight loss drug cost calculator compares monthly prescription costs across all major UK and US providers.

What is a normal menstrual cycle?

The American College of Obstetricians and Gynecologists (ACOG) defines a normal menstrual cycle as any cycle between 21 and 35 days in length. The widely cited average of 28 days reflects the population central tendency but should not be treated as a target: most people do not have exactly 28-day cycles, and significant natural variation exists both between individuals and within a single person's cycles from month to month.

Period duration, meaning the number of days of bleeding, is considered normal in the range of 3 to 7 days. Cycle length is not static across a person's reproductive lifespan. Cycles tend to be more irregular in the years immediately after menarche (first period) and again in the perimenopause years. In the mid-reproductive years (late 20s to mid-30s), cycles tend to be most regular. From the late 30s onward, cycles often shorten and become less predictable as ovarian reserve declines.

Large-scale menstrual health data from tracking app populations (Clue and Apple Women's Health Study) broadly confirms ACOG clinical guidance, while also revealing that cycle length varies more between people than within the same person over time. Use is my period normal to compare your cycle data, or the period calculator to predict upcoming dates based on your personal pattern.

What is the average age of menopause?

Natural menopause, defined as 12 consecutive months without a menstrual period in the absence of surgery or medical intervention, occurs at an average age of 51 in the United States and United Kingdom. Data from the NHS and the North American Menopause Society (NAMS) place the clinically normal range at 45 to 55 years. Menopause occurring before age 40 is classified as premature ovarian insufficiency (POI) and affects approximately 1% of women.

Perimenopause, the transitional phase preceding the final menstrual period, typically begins 4 to 8 years before menopause and is characterised by irregular cycles, hormonal fluctuations, and early vasomotor symptoms such as hot flushes. Many people experience perimenopause symptoms from their mid-40s without recognising the clinical transition that is underway.

Surgical menopause, triggered by bilateral oophorectomy (removal of both ovaries), can occur at any age and tends to produce more abrupt symptoms than natural menopause. Certain medical treatments including chemotherapy and pelvic radiation therapy can also induce premature menopause. For personalised staging, use the menopause stage calculator or the perimenopause quiz to assess whether your symptoms match the perimenopause profile.

How much caffeine does the average person consume?

FDA and NHANES data indicate that the average US adult consumes approximately 200mg of caffeine per day, equivalent to roughly two standard 8-ounce cups of brewed coffee. Approximately 85% of US adults consume at least one caffeinated beverage on any given day, making caffeine the most widely consumed psychoactive substance in the world. The FDA's recommended upper limit for healthy adults is 400mg per day; intake above this level is associated with adverse effects including anxiety, insomnia, elevated heart rate, and in rare cases at very high doses, cardiac arrhythmia.

Caffeine metabolism varies substantially between individuals, driven primarily by activity levels of the CYP1A2 enzyme in the liver. The half-life of caffeine (the time taken to metabolise half the dose) ranges from 3 to 7 hours in most adults, but can be shorter in heavy smokers and longer in pregnant women or those taking certain medications. This means a 200mg dose consumed at 3pm may still be active at bedtime for slow metabolisers, meaningfully disrupting sleep architecture even when subjective sleepiness is not reported.

Caffeine intake tends to peak in the 35 to 54 age group and is somewhat lower among young adults (18 to 24). Coffee accounts for approximately 64% of US caffeine intake, followed by tea, soft drinks, and energy drinks. Use the caffeine clearance calculator to estimate how much caffeine remains in your system at any given time based on your intake and timing.

How common are digestive conditions?

Functional gastrointestinal disorders are among the most prevalent chronic health conditions worldwide, yet they are systematically under-reported and under-diagnosed. The Rome Foundation, which establishes diagnostic criteria for functional GI disorders, estimates that irritable bowel syndrome (IBS) affects 10 to 15% of the global population. Despite this prevalence, only approximately 30% of those affected seek medical care, meaning the majority manage their symptoms without a formal diagnosis.

Gastroesophageal reflux disease (GERD) affects approximately 20% of Western populations on a weekly or more frequent basis, making it one of the most common GI diagnoses in primary care. Functional dyspepsia (chronic indigestion without a structural cause) affects a further 10 to 15%. Chronic constipation, defined as fewer than three bowel movements per week with associated symptoms, affects approximately 15% of adults. Coeliac disease (an autoimmune response to gluten) affects approximately 1% of the population in Western countries, though a substantial proportion remain undiagnosed.

Digestive symptom burden overlaps significantly across conditions, and many individuals with functional GI disorders also report comorbid anxiety or depression. Use do I have IBS to assess whether your symptoms match the IBS profile, or the bloating symptom checker for a broader symptom-to-condition mapping.

What are average cancer survival rates?

NCI SEER (Surveillance, Epidemiology, and End Results Program) data shows that the overall 5-year relative survival rate for all cancers combined is approximately 68%, a figure that has improved significantly from 49% in the early 1970s. This improvement reflects advances in early detection, surgical technique, chemotherapy protocols, targeted therapies, and immunotherapy. The survival figure refers to relative survival: the likelihood that someone with cancer survives at least five years relative to someone without the diagnosis.

Survival rates vary enormously by cancer type. Thyroid cancer (98% 5-year survival) and melanoma caught at an early stage have among the best prognoses. Pancreatic cancer (approximately 12%) and glioblastoma (approximately 7%) remain among the most lethal diagnoses. Stage at diagnosis is the dominant factor: for most solid tumours, 5-year survival for localised (early-stage) disease is two to four times higher than for distant (metastatic) disease. Approximately 5 to 10% of all cancers are attributable to inherited genetic mutations, the majority of the rest arising from a combination of environmental exposures, lifestyle factors, and stochastic cellular mutations.

The SEER data shows that cancer incidence and survival both vary substantially by age, sex, race, and geography. For condition-specific context and risk framing, see the cancer survival rates page.

How common is vitamin deficiency?

NHANES data consistently finds that micronutrient deficiencies are more widespread in the US population than most people assume. Vitamin D deficiency (serum 25-hydroxyvitamin D below 20 ng/mL) affects approximately 42% of US adults. This proportion is substantially higher in groups with limited sun exposure, darker skin tones (which produce less vitamin D from sunlight), older adults, and those with obesity. Vitamin D plays roles in bone health, immune function, and cardiovascular regulation; widespread deficiency has significant population-level health implications.

Iron deficiency, the most common nutritional deficiency globally, affects approximately 10% of women of reproductive age in the United States. The rate rises to 15 to 20% among pregnant women. Iron deficiency can cause fatigue, impaired cognitive function, and anaemia; in pregnant women it is associated with adverse birth outcomes. Men and postmenopausal women have substantially lower iron deficiency rates.

Vitamin B12 deficiency affects approximately 6% of US adults under 60 and up to 20% of those over 60. B12 is found almost exclusively in animal-derived foods, meaning vegetarians and vegans are at significantly elevated risk. Older adults are also at risk due to declining gastric acid production, which impairs B12 absorption. Use the vitamin deficiency quiz for a personalised risk assessment, or check safe supplementation thresholds with the supplement safe dose checker.