Reference
Figures you can check, not just read
These pages exist to answer one question each: a table to look something up in, a number to run, a source you can verify. They are updated when the underlying rules or figures change, and each one shows the date its figures were last checked.
Reference Blood Pressure
Blood pressure categories: where a reading actually falls
Enter the two numbers and see which published category the reading lands in — normal, elevated, stage 1, stage 2 or crisis — and which number decided it.
Reference Sleep and Recovery
Sleep by age: the row that applies, and where eight sits
The CDC's nine age rows, the three panels behind them, and what eight hours means in each adult row — a floor at 18–60, a midpoint, a ceiling after 65.
Reference Everyday Nutrition
Caffeine by drink, added up against 400 mg
Typical caffeine for coffee, tea, soft drinks and energy drinks, and a running total against the FDA's 400 mg figure for most adults, kept as a range.