Becoming a medical assistant is rewarding. Why? Because they are on the front line, working to keep all of us healthy. Medical assistants have a wide range of responsibilities, but among the most impactful is taking vital signs. These essential measurements of bodily function are taken at each visit and used by the doctor to make sound clinical decisions. Taking vital signs isn’t complicated, but it is technical, and accuracy is a must for medical assistants.

What are Vital Signs?

Vital signs are measures of the body’s basic functions. Taking vital signs help physicians assess a patient’s general health, diagnose disease, monitor the effects of treatments, and calculate medication dosages. Vital signs are taken before each exam by medical assistants because patterns in readings over time are often more meaningful than a single result.

There are four primary vital signs that a medical assistant takes: temperature, blood pressure, respiratory rate and pulse, or heart rate. Additional measures of clinical significance that may or may not be included in a set of vital signs include height, weight, Body Mass Index (BMI) and peripheral oxygen saturation.

Which vital signs a doctor asks for depends in part on their specialty and the patient’s physical complaints. Oxygen saturation, for example, is a less valuable measure of health for a podiatrist than for a cardiologist or pulmonologist.

Abnormal vital signs may be more or less concerning based on a patient’s condition. For example, a sudden weight gain for a patient with heart failure requires immediate attention, while the same change in an otherwise healthy patient warrants a “wait and see” approach. Similarly, a single high blood pressure reading could be related to recent activity, caffeine intake or anxiety, while a pattern of above-normal measurements likely indicates hypertension.

Vital Sign #1: Temperature

A healthy adult body temperature ranges from 97.8 to 99 °F. The Centers for Disease Control and Prevention (CDC) define a fever as 100.4 °F (38 °C) or higher. Temperatures up to 102.9 °F are considered low-grade fevers, readings over 103 °F are high-grade fevers. Both can indicate many of the same disorders, including infection, inflammation and physiological stress, but high-grade fevers carry a higher risk of severe complications, such as febrile seizures.

Too-low body temperatures are rare, but causes may include malnutrition, vitamin deficiencies and infections so severe that they overwhelm the body’s immune system.

Medical assistants take body temperature with one of these five common methods including oral, aural, tympanic, temporal, and rectal.

Oral Temperature

This measures body temperature under the tongue. The models used in doctor’s offices come with single-use disposable covers for safety and are accurate to one-tenth of a degree. Older glass thermometers filled with hazardous mercury are no longer in use.

Patients shouldn’t drink hot or cold liquids for ten minutes before having their temperature taken, and their mouth should create a tight seal around the probe for best results. Patients with respiratory disease who breathe through their mouth may require an alternative method.

Aural or Tympanic

A medical assistant places a thermometer in the ear. This measures the temperature of the eardrum, or tympanic membrane, with infrared rays. Accurate readings depend on proper technique, probes must seal off the ear canal. Scarring from infections or heavy accumulations of earwax can affect measurements.

Temporal

Temporal or “forehead” thermometers measure temperature over the temporal artery. The process takes only a few seconds, and it’s well-tolerated by both adults and children. But because the results are among the least accurate, temporal thermometers are used only for screening. It is important to recheck temperature using a second method for abnormal results.

Rectal

This temperature is the most accurate, but can be unpleasant and sometimes risky. Probes inserted in the rectum can damage or even perforate the intestinal lining. Taking rectal temperatures in an office setting is now rare.

Vital Sign #2: Pulse

Arteries close to the skin’s surface pulsate each time the heart beats, creating a convenient way to measure heart rate without using a stethoscope. Large surface arteries are located in the neck, groin, temple and feet, but the radial artery at the wrist is the most accessible and commonly used.

Medical assistants measure heart rate by counting the number of pulsations in the artery in 60 seconds. A shortcut is to count pulses for 15 seconds and multiply the result by four. The normal heart rate for adults is 60–100 beats per minute, but children may have pulses as high as 140. Conditioned athletes can have healthy heart rates as low as 60.

Noting a pulse’s rhythm is also essential. Skipped beats or fluctuation in the speed of a patient’s heart rate suggest a primary arrhythmia, an umbrella term for a group of disorders affecting heart rhythm.

Common arrhythmias include atrial fibrillation and bradycardia, an abnormally low heart rate. Abnormal heart rates and rhythms may also be due to medication side effects and health conditions ranging from thyroid disease to infection.

Vital Sign #3: Respirations

The respiratory rate is the number of breaths a patient takes per minute. Because unintentional changes in breathing patterns can occur due to anxiety, medical assistants evaluate respirations by watching the chest rise and fall without the patient knowing it.

Normal adult respirations should be relaxed and number 12–16 per minute. A rate higher than average could indicate pain, fever or shortness of breath, while a low rate suggests a medical condition, such as a pulmonary disorder or a drug overdose.

Vital Sign #4: Blood Pressure

Blood “pressure,” or BP, is the force with which blood pushes against arterial walls. Recorded as two distinct readings, the “systolic” blood pressure, measured when the heart contracts, over the “diastolic” blood pressure, measured when it’s relaxed, it reflects how well the cardiovascular system is working.

BP is measured using one of two methods, auscultation, meaning “listening,” the type requiring a sphygomanometer and a stethoscope, and oscillometric, a newer method using a digital monitor. Medical assistants learn both processes.

Why is blood pressure important? Low blood pressure can indicate dehydration, a risk factor for infection and organ failure. High blood pressure, also known as hypertension, is a leading risk factor for life-threatening medical conditions, including heart disease, renal failure and stroke.

Blood Pressure readings less than 120/80 are considered ideal. Hypertension, the term used for consistently high blood pressure, is divided into four stages:

Stage 1

Stage 1 or prehypertension is characterized by blood pressure between 120/80–138/89. Single readings in this range are not usually worrisome, but a trend reflects an increased risk of disease.

Lifestyle changes, including exercise and heart-healthy diet, are the first line of defense against high blood pressure, but patients with other risk factors, such as diabetes, may be prescribed mild medication.

Stage 2

Mild or Stage 2 hypertension is diagnosed when three or more BP readings are between 140/90–149/99. At this point, most doctors will prescribe medication in addition to lifestyle changes because untreated blood pressure in this range raises the risk of heart attack and stroke.

Stage 3

Stage 3 blood pressure from 150/100–159/109 signals moderate hypertension with a significant risk of heart and kidney complications. More aggressive treatment, including daily monitoring and medications, may be necessary. Medical assistants can help by teaching patients how to take their blood pressure accurately at home.

Stage 4

Severe or Stage 4 hypertension is marked by blood pressure greater than 159/109. While most cases of hypertension are asymptomatic, patients with a BP this high may report headaches, anxiety or shortness of breath. Blood pressure of 180/120 or higher is known as malignant hypertension. It’s a rare but life-threatening emergency.

Vital Sign #5: Height

Height is important enough to call a vital sign for two reasons. It’s one of the two factors used to calculate Body Mass Index (BMI), a measure that better reflects the health of a patient’s body mass than does weight alone. Doctor’s use BMI to determine dosages for a broad array of medications.

Height also becomes a crucial vital sign as patients age, especially for women. A decrease of an inch or more is often the first symptom to signal osteoporosis, thinning of the bones, and the need for a bone density test.

Accuracy is critical when measuring height because small losses are difficult to detect from visit to visit. Medical assistants should use the same method each time.

Vital Sign #6: Weight

Weight is the second factor used to determine BMI, so it’s useful for predicting general health and calculating drug dosages. It also has significant clinical implications for patients with specific disorders. Gaining just a pound can cause shortness of breath in patients with congestive heart failure. As with weight, using the same scale and a consistent method of measurement is the key to accurate results.

Vital Sign #7: Peripheral Oxygen Saturation

Peripheral oxygen saturation reflects how well the tissues furthest away from the heart are perfused. Reported as a percentage, it helps doctors understand how effectively a patient’s cardiovascular system is working.

Medical assistants check oxygen saturation with a convenient fingertip device called a pulse oximeter. Oximeters use light technology to measure the concentration of hemoglobin in blood to determine how much oxygen is present. Readings from 95-100 percent are considered normal.

While pulse oximetry is not a routine vital sign in all practices, it’s becoming more mainstream because it’s simple to take, and the results add depth to the clinical picture. Oximeters are now available over-the-counter for home use. Taking a reading is as straightforward as attaching the device to the fingertip, but cold fingers and nail polish can cause inaccurate results.

Final Thoughts

Taking vital signs isn’t complex, but it requires basic health knowledge, technical skills and a contentious approach. It’s a perfect task for a trained medical assistant.

Did learning about how medical assistants take vital signs interest you? Ready to learn more about becoming a medical assistant? Meridian College offers hands–on Medical Assistant training from experienced school faculty who know how to prepare you for the daily challenges you’ll face on the job. From assisting doctors with patients to important administrative tasks, our experienced Medical Assistant program teachers will train you for a rewarding new career.

In addition to receiving training from school instructors with real-world experience, you will also complete a school externship in a physician’s office, clinic or related healthcare facility under the supervision of a physician, nurse or health services professional to further develop your skills.

Contact Meridian College today to learn more about becoming a medical assistant.