Your numbers, explained
Five vital signs tell a doctor how your body is doing right now. A handful of blood tests tell how it is doing over time. Here is what is normal, and what to do when a number is off.
Watch: the narrated video (4 minutes)
The five vital signs
Blood pressure
Blood pressure is written as two numbers, like 128/82. The top (systolic) is the pressure when your heart beats; the bottom (diastolic) is the pressure between beats. High blood pressure usually has no symptoms, which is why it is called the silent killer: over years it damages the heart, brain, kidneys and eyes.
The 2025 American Heart Association and American College of Cardiology guideline keeps these categories, sets a goal under 130/80 for most adults, and encourages getting the top number under 120 when you can do it safely. Lifestyle changes alone can lower the top number by 5 to 10 points: less salt, more fruits and vegetables, regular walking, less alcohol, and losing weight if needed.
How to take your blood pressure at home
- Use a validated upper-arm cuff (check validatebp.org) in the right size. Wrist and finger devices are less accurate.
- No caffeine, exercise or smoking for 30 minutes, and empty your bladder.
- Sit quietly for 5 minutes with your back supported, feet flat, legs uncrossed.
- Rest your arm on a table with the cuff at heart level, on bare skin.
- Don't talk. Take 2 readings a minute apart, morning and evening, and write them down or let the cuff store them.
- Bring the log to your doctor. A week of home readings tells more than one office reading.
Pulse and oxygen
Pulse: press two fingers on the inside of your wrist below the thumb, count the beats for 30 seconds and double it. A resting rate of 60 to 100 is normal; fit people are often in the 50s. A racing, very slow, or irregular pulse with dizziness, fainting or chest pain needs care right away.
Oxygen (SpO2): a fingertip pulse oximeter reads 95 to 100% in most healthy people. Readings below 92%, or a drop with shortness of breath, need prompt care. Cold fingers, nail polish and darker skin can make readings less accurate, so trust how you feel too.
Fever
| Who | Fever | Call the doctor or get care when |
|---|---|---|
| Babies under 3 months | 100.4 °F (38 °C) or higher, taken rectally | Right away, day or night |
| Children | 100.4 °F or higher | Fever over 3 days, trouble breathing, stiff neck, won't drink, very sleepy or hard to wake |
| Adults | 100.4 °F or higher | Over 103 °F, lasts more than 3 days, or comes with stiff neck, confusion, rash, chest pain or trouble breathing |
Checkup numbers
Members get the full lab tests explained guide, line by line through a blood count, a metabolic panel, thyroid, urine and more.
Sources
Checked November 11, 2026.