Normal vital signs for a healthy resting adult fall within these ranges: a heart rate of 60 to 100 beats per minute, blood pressure below 120/80 mmHg, a respiratory rate of 12 to 18 breaths per minute, and a body temperature averaging 98.6°F (37°C). These four measurements give a quick snapshot of how well your body’s most basic functions are working. Here’s what each one means, how the numbers shift across age groups, and when a reading should concern you.
The Four Core Vital Signs in Adults
Heart rate (pulse): 60 to 100 beats per minute at rest. Your pulse reflects how hard your heart is working to circulate blood. Well-trained endurance athletes can have a resting heart rate as low as 40 beats per minute, which is normal for them because their hearts pump more blood with each beat. For everyone else, a consistently low or high resting pulse outside the standard range is worth investigating.
Blood pressure: less than 120/80 mmHg is considered normal. The top number (systolic) measures pressure when your heart contracts; the bottom number (diastolic) measures pressure between beats. The 2025 guidelines from the American Heart Association and American College of Cardiology classify blood pressure into four categories:
- Normal: below 120 systolic and below 80 diastolic
- Elevated: 120 to 129 systolic with diastolic still below 80
- Stage 1 hypertension: 130 to 139 systolic or 80 to 89 diastolic
- Stage 2 hypertension: 140 or higher systolic, or 90 or higher diastolic
If your systolic and diastolic numbers fall into two different categories, the higher category applies.
Respiratory rate: 12 to 18 breaths per minute. Most people never think about their breathing rate because it’s regulated automatically. Anxiety, fever, pain, and lung conditions can all push it higher. A rate above 22 in an adult is considered a clinical red flag.
Body temperature: 97.7°F to 99.1°F (36.5°C to 37.3°C), with 98.6°F as the classic average. Your temperature fluctuates throughout the day, typically running lowest in the early morning and peaking in the late afternoon. Where you measure also matters. Rectal readings are the most accurate reflection of core body temperature. Armpit (axillary) readings tend to run lower than core temperature and can lag behind rapid changes, making them less reliable. Forehead and ear readings fall somewhere in between.
Oxygen Saturation: The Unofficial Fifth Vital Sign
Pulse oximetry, the small clip placed on your fingertip, measures the percentage of your red blood cells carrying oxygen. A normal reading is 95% to 100%. Readings below that threshold indicate your blood isn’t picking up enough oxygen from your lungs, a condition called hypoxemia.
If your home pulse oximeter shows 92% or lower, contact a healthcare provider. A reading of 88% or lower is a medical emergency. Keep in mind that nail polish, poor circulation, cold fingers, and darker skin pigmentation can all affect the accuracy of these devices.
Pain was once promoted as a “fifth vital sign” in the late 1990s, when the American Pain Society urged clinicians to assess pain alongside the traditional four measurements. That push, while well-intentioned, contributed to the overprescription of painkillers. Oxygen saturation has since become the more commonly tracked additional measurement in clinical settings.
Normal Vital Signs in Children
Children are not small adults when it comes to vital signs. Their hearts beat faster and they breathe more rapidly, with both rates gradually slowing as they grow. Here’s what’s typical:
Heart rate varies dramatically by age. A newborn’s awake heart rate ranges from 85 to 205 beats per minute. Between 3 months and 2 years, the awake range is 100 to 190. From ages 2 to 10, it drops to 60 to 140. By age 10 and older, children settle into the adult-like range of 60 to 100 while awake. During sleep, all of these ranges run lower, with sleeping infants typically between 80 and 160 and sleeping school-age children between 60 and 90.
Respiratory rate follows a similar pattern. Infants breathe 30 to 60 times per minute. Toddlers slow to 24 to 40, preschoolers to 22 to 34, and school-age children to 18 to 30. By adolescence, the rate settles to 12 to 16 breaths per minute.
Blood pressure in children is trickier because normal readings depend on age, height, and sex. As a general rule, dangerously low systolic pressure in children ages 1 to 10 can be estimated with a simple formula: 70 plus twice the child’s age in years. So for a 4-year-old, a systolic reading below 78 mmHg would signal concern. For newborns, systolic pressure below 60 mmHg is considered hypotensive; for infants up to 12 months, below 70 mmHg.
How Vital Signs Change With Age
Resting heart rate stays roughly the same as you get older, but your cardiovascular system responds to exercise differently. It takes longer for your pulse to rise during physical activity and longer for it to return to baseline afterward. Your maximum achievable heart rate during exercise also declines with age.
Blood pressure tends to creep upward over the decades, and the risk of hypertension increases significantly after 65. Older adults are also more prone to orthostatic hypotension, a sudden drop in blood pressure when standing up that can cause dizziness or lightheadedness.
Temperature regulation becomes less reliable with aging. You lose some of the insulating fat beneath your skin, making it harder to stay warm. Your ability to sweat decreases, which makes overheating more likely. Perhaps most importantly, older adults with infections may not develop a noticeable fever. A “normal” temperature reading in a sick older person doesn’t necessarily mean the infection is mild.
When Vital Signs Signal an Emergency
Individual readings matter less than context. A pulse of 105 after climbing stairs is unremarkable; the same reading while sitting still deserves attention. That said, certain thresholds are treated as red flags in clinical settings regardless of circumstances:
- Temperature: 102°F or higher
- Heart rate: below 50 or above 110 beats per minute at rest
- Respiratory rate: above 22 breaths per minute, or any visible breathing difficulty
- Oxygen saturation: below 94% on room air
- Blood pressure: systolic above 180 or below 90, or diastolic above 120 or below 60, especially with symptoms like headache, chest pain, dizziness, slurred speech, weakness on one side, or shortness of breath
For pregnant individuals, the blood pressure thresholds are tighter: systolic above 140 or below 90, and diastolic above 90 or below 60, all warrant prompt evaluation. In infants under 2 months, a rectal temperature of 100.4°F or higher is treated as a potential emergency because their immune systems are too immature to localize infections reliably.