Why do we care so much about vital signs? At every clinic visit we check your blood pressure, your heart rate, your temperature, etc. Do you ever wonder what we are looking for with these measurements? What’s normal? What’s abnormal? This quick reference guide provides you the basic numbers and information on vitals. However, I do not recommend you use this vital signs guide in lieu of medical advice, because each patient can have different heart rate or blood pressure goals, for example. So ask your doctor if you have specific questions. This is a basic reference guide, not meant to be taken as medical advice.

Blood Pressure

Your blood pressure is measured using two numbers, like 120/80, for example. The top number is called the systolic blood pressure and the bottom number is called the diastolic blood pressure. In basic terms, the systolic blood pressure is the force of the blood leaving the heart, and the diastolic pressure is the force of the blood filling the heart again. We measure your blood pressure using a stethoscope and a blood pressure cuff. It is important that we check your blood pressure using the correct cuff size. If you have a larger arm, then your blood pressure will need to be checked with a larger cuff. Measuring your blood pressure with a cuff that is too small will artificially elevate your blood pressure reading while measuring with a cuff that is too large will artificially lower your blood pressure.

We measure blood pressure in mmHg (millimeters of mercury). A normal systolic blood pressure can range between 140-90 mmHg and a normal diastolic blood pressure can range between 90-60 mmHg. However, your doctor may have different blood pressure goals for you, based on your medical history. See the recent ACC/AHA guidelines for more detailed info.

Heart Rate

Your heart rate is the number of times your heart beats per minute. You can measure your heart rate by simply checking your pulse and counting the number of beats you have in 60 seconds. A normal heart rate ranges between 60-100 beats per minute (bpm). However, your heart rate can dip down into the 50s if you are physically fit or if you are sleeping and this is usually not a problem. On the flip side, when you exercise, your heart rate should increase as your effort increases. Your maximum predicted heart rate is calculated by subtracting your age from 220. So, if you are 50 years old, then your max predicted heart rate is around 220-50 = 170 bpm.

Temperature

The average human body temperature is 98.6 degrees Fahrenheit or 37 degrees Celsius. That being said, your temperature can range between 96 degrees F and 100.3 degrees F even when nothing is wrong. A temperature above 100.4 degrees F or 38 degrees C is considered a fever. Even if your baseline temperature is a little on the low side, like 96 degrees F, for example, you still don’t have a fever until the thermometer reaches 100.4 degrees F. Although infections like viruses and bacteria are the most common causes of fever, lots of other conditions can raise your temperature, as well. For example, abnormal temperatures can come from immune system responses, like getting a vaccine, drug reactions including illicit drugs, and certain kinds of malignancies, just to name a few.

Respiratory Rate

The respiratory rate is the number of breaths you take per minute. This gives your doctor a good estimate of how hard you have to work to breathe. A normal respiratory rate is between 12-20 breaths per minute in a normal healthy adult. A respiratory rate below 12 can indicate that something is inhibiting your body’s respiratory drive. The most common culprits are drugs like narcotics, alcohol and benzodiazepines. A respiratory rate above 20 can indicate respiratory distress, meaning you are having to work excessively hard to breathe normally. The higher the respiratory rate, the more concerning it is. Panic attacks, asthma attacks, metabolic acidosis, or anything that lowers your oxygen level can cause an elevated respiratory rate.

Oxygen Saturation

Frequently displayed as SpO2 (saturation percentage of oxygen), this is your blood oxygen level. Oxygen saturation is measured by a pulse oximeter, which measures the oxygen level in your blood with a light that shines on the capillaries in your finger. Normal blood oxygen level is between 90-100%. And the lower your oxygen level drops below 90%, the more emergent your situation may be. Patients with chronic lung disease may need to wear oxygen to keep their oxygen saturation above 90%.

Body Mass Index

Your body mass index (BMI) is your height to weight ratio. It tells us how your body weight compares to the ideal weight for your height. As I discussed in my article Staying Trim Around the Holidays, a BMI of 18-25 is considered normal. If you are curious, you can calculate your own BMI using this MedCalc Calculator.

This article is meant to provide you with a quick reference to know what your vital signs are and what we consider to be average ranges. Remember, these are averages and may not apply to your specific medical situation. Vital signs recommendations can vary so please consult with your doctor. If you would like to buy some of the equipment I mentioned above in order to monitor your vital signs at home, then you can check out some recommendations on my Patient Resources page.

Also, if you are interested in other quick guides, then you can check out my other references here!

Need more wellness? Read my previous article on Prostate Cancer Screening.