The Sleep Guide
Most adults need 7 to 9 hours of sleep a night, and consistency matters as much as duration. Sleep quality is shaped by a regular schedule, morning light, caffeine…
Health Guides
Thirty-eight practical, deeply researched guides across nine clusters. Each one answers the question first, then shows you what to do about it — and points to the next guide worth reading.
Jump to a cluster
Nine clusters, grouped the way health actually works rather than the way a filing cabinet does.
Cluster 1 of 9
Everyday Health
The five or six habits that do most of the work: sleep, food, water, movement, stress, and mental wellbeing.
The Nutrition Guide
The strongest nutrition evidence supports whole dietary patterns rather than single foods or nutrients. Mediterranean-style and DASH eating patterns — built on…
The Hydration Guide
There is no single daily water number that fits everyone. General guidance lands around 2.7 litres of total fluid a day for women and 3.7 litres for men, including…
The Fitness Guide
US Physical Activity Guidelines recommend that adults get 150 to 300 minutes a week of moderate-intensity aerobic activity, or 75 to 150 minutes of vigorous…
The Stress Guide
Stress is the body's response to demand, driven largely by adrenaline and cortisol. Short bursts are normal and useful; sustained activation is linked to high blood…
The Mental Wellness Guide
Mental wellness is the day-to-day capacity to handle stress, connect with people, and function — not the absence of difficult feelings. Sleep, physical activity,…
The Alcohol and Health Guide
Current guidance from major health bodies is that less alcohol is better for health, and no amount has been established as beneficial. US guidelines suggest that…
Cluster 2 of 9
Metabolic Health
How weight, blood sugar, insulin sensitivity, cholesterol, and blood pressure fit together — and what actually moves them.
The Weight Guide
Body weight is regulated by biology, environment, and behaviour together — not willpower alone. Sustainable change usually comes from a modest energy deficit built…
The Blood Sugar Guide
Blood glucose is the sugar circulating in your blood, tightly regulated by insulin and other hormones. Common markers are fasting glucose, A1C (a 2 to 3 month…
The Insulin Resistance Guide
Insulin resistance means cells respond less effectively to insulin, so the pancreas must produce more to keep blood glucose in range. It often develops silently over…
The Cholesterol Guide
A standard lipid panel measures total cholesterol, LDL, HDL, and triglycerides. LDL cholesterol is the main target because it drives plaque build-up in artery walls;…
The Blood Pressure Guide
Blood pressure is written as systolic over diastolic. Under 2017 ACC/AHA categories, normal is below 120/80 mmHg; 120-129 systolic with diastolic under 80 is…
Cluster 3 of 9
Healthy Aging
Protecting strength, balance, bone, and brain so that added years stay useful years.
The Mobility Guide
Mobility is the ability to move joints through useful range and get around independently. It declines with inactivity more than with age itself. Strength training,…
The Muscle Guide
Muscle mass and strength decline gradually from around midlife if nothing is done, a process called sarcopenia. Muscle stores glucose, supports bone, and underpins…
The Brain Health Guide
Brain health in later life is shaped substantially by the same factors that affect the heart: blood pressure, blood sugar, lipids, smoking, and activity. Sleep,…
The Longevity Basics Guide
The evidence for living longer in good health points repeatedly to the same unglamorous set: not smoking, regular physical activity, a plant-forward eating pattern,…
The Bone Health Guide
Bone is living tissue that is constantly rebuilt. Peak bone mass is reached by roughly the late twenties, after which maintaining it depends largely on mechanical…
The Preventive Care Guide
Preventive care covers screening tests, vaccinations, counselling, and risk assessment intended to catch problems early or prevent them entirely. Recommendations…
Cluster 4 of 9
Heart Health
The numbers that drive cardiovascular risk, and the eating and activity patterns with the strongest evidence behind them.
Blood Pressure and Your Heart
High blood pressure forces the heart to work harder and damages artery walls over time, contributing to heart attack, stroke, heart failure, and kidney disease.…
Cholesterol and Your Heart
LDL particles deposit cholesterol in artery walls, where it triggers inflammation and forms plaque. Plaque narrows arteries and, if it ruptures, can cause a heart…
Understanding Your Cardiovascular Risk
Cardiovascular risk is an estimate of the chance of a heart attack or stroke over a defined period, usually ten years, based on age, sex, blood pressure,…
Exercise for Heart Health
Regular physical activity lowers blood pressure, improves cholesterol and insulin sensitivity, helps with weight, and improves the function of blood vessels and the…
The Heart-Healthy Eating Guide
The eating patterns with the strongest cardiovascular evidence are the Mediterranean and DASH patterns. Both emphasise vegetables, fruit, legumes, whole grains,…
Cluster 5 of 9
Men's Health
Screenings worth keeping on schedule, cardiovascular risk in men, and mental health that too often goes unspoken.
Health Screenings for Men
Screening for men centres on cardiovascular risk factors from early adulthood, colorectal cancer screening from 45, and age-appropriate cancer and infection…
Heart Health for Men
Heart disease is the leading cause of death among men in most high-income countries, and men tend to develop it around a decade earlier than women on average. The…
Men's Mental Health
Men experience depression and anxiety at substantial rates but are diagnosed and treated less often, and die by suicide at higher rates in most countries. Symptoms…
Cluster 6 of 9
Women's Health
Screening schedules across the decades, bone health through menopause, and heart disease in women.
Health Screenings for Women
Screening for women includes cervical cancer screening from age 21, breast cancer screening beginning in the forties, colorectal cancer screening from 45, bone…
Bone Health for Women
Bone loss accelerates in the years around menopause as oestrogen falls, which is why osteoporosis is more common in women. Resistance and weight-bearing exercise,…
Heart Health for Women
Cardiovascular disease is the leading cause of death in women in most high-income countries, yet it is frequently underestimated and under-treated. Risk rises after…
Cluster 7 of 9
Cancer & Prevention
What screening can and cannot do, the exposures that matter most, and sun protection that works.
The Cancer Screening Guide
Cancer screening looks for cancer before symptoms appear. Screening with strong evidence includes colorectal cancer from age 45, cervical cancer from 21, breast…
Reducing Your Cancer Risk
A substantial share of cancers is linked to modifiable factors. The strongest are tobacco use, excess body weight, alcohol, ultraviolet exposure, physical…
The Skin Protection Guide
Ultraviolet radiation from the sun and tanning beds is the main preventable cause of skin cancer. Protection combines shade during peak hours, clothing and a hat,…
Cluster 8 of 9
Digestive Health
How digestion works, why fiber matters more than almost any single food, and habits that ease reflux.
The Gut Health Guide
Digestion breaks food into absorbable components across the mouth, stomach, small intestine, and colon, with the liver, gallbladder, and pancreas contributing. The…
The Fiber Guide
Fiber is the part of plant food the body cannot digest. General guidance is roughly 25 to 38 grams a day depending on age and sex, and most adults get about half…
Habits That Ease Reflux
Reflux occurs when stomach contents move up into the oesophagus, usually because the lower oesophageal sphincter relaxes at the wrong time or pressure in the abdomen…
Cluster 9 of 9
Brain Health
What the evidence supports for protecting thinking and memory — sleep, stress, movement, and vascular health.
The Cognitive Health Guide
Cognitive health covers memory, attention, language, and reasoning. Some slowing of processing speed and word retrieval is common with age; losing the ability to do…
Sleep and Your Brain
Sleep is an active process during which the brain consolidates memory, regulates emotion, and clears metabolic waste. Short or fragmented sleep impairs attention,…
Stress and Your Brain
Short-term stress sharpens attention and can improve memory for the stressful event itself. Chronic stress works differently: sustained cortisol exposure is…
How our guides are built
Every guide on this page follows the same order, so you always know where to find the part you came for.
Direct answer
The first block answers the question in a short paragraph you can read in ten seconds — no scrolling, no preamble.
Key takeaways
Three to five one-sentence points. If you read nothing else, read these.
The sections
Four to six numbered sections in a table of contents, each with a stable link so you can send someone straight to the part that matters.
Do this today
A short checklist of small, specific actions that fit inside a normal week — not a programme you have to rearrange your life around.
Questions and answers
The questions people actually ask, answered plainly, plus the related questions worth following up.
Sources
Links to the public-health and clinical organisations the guide draws on, so you can read the original material yourself.
Our updated-date policy
The date on a guide is the date its content was last reviewed against current public-health guidance — not the date a typo was fixed. We re-check every guide at least once a year, and sooner when a major body changes its recommendation. When a change alters what we advise, we say what changed rather than quietly editing. Read our editorial policy and corrections policy.
Who writes them
Guides are written and reviewed by the Health Captain Editorial Team and labelled Editorially Reviewed. We never label something medically reviewed unless a credentialed professional has actually reviewed it — see our medical review policy and sources policy.
From the blog
New writing from Health Captain
Guides are the reference material. The blog is where we cover what changed this week.
Sleep
How Much Sleep Adults Actually Need, and Why Consistency Matters
Seven to nine hours covers most adults, but a steady wake time may do more for how you feel than the total on any single night.
Longevity
Longevity: Separating the Evidence From the Marketing
No supplement has been shown to extend human lifespan. Six questions help you evaluate any longevity claim before you spend money on it.
Cancer & Prevention
Cancer Screening: What It Can Do, and What It Costs You
Colorectal screening from 45 is among the highest-value tests available. Overdiagnosis and false positives are the other half of the conversation.