Vital Signs Are Not Part of the General Survey
Vital signs are not considered a component of the general survey—they are measured separately as objective physiological parameters distinct from the observational assessment that comprises the general survey.
Understanding the General Survey
The general survey is the observational component of the physical examination that begins the moment you encounter the patient. It encompasses:
- Facial expression and affect - noting emotional state, distress, or unusual features
- Level of consciousness - assessing alertness, orientation, and cognitive function
- Skin appearance and obvious lesions - observing color, texture, rashes, or visible abnormalities
- Posture, gait, and motor activity - evaluating body positioning, movement patterns, and coordination
- Body habitus including BMI assessment - observing overall body build and proportions 1
Why Vital Signs Stand Apart
Vital signs (blood pressure, heart rate, respiratory rate, temperature, and oxygen saturation) are measured physiological parameters rather than observed characteristics. They require instrumentation and represent quantitative data collection that occurs after the initial observational survey.
The Role of BMI in Physical Assessment
While BMI calculation requires measurement (height and weight), the visual assessment of body habitus is part of the general survey. BMI itself is considered a screening tool and anthropometric measure that, while easy to calculate, has significant limitations 1:
- BMI does not distinguish between lean and fat mass 1
- It fails to account for body fat distribution, an independent risk factor 1
- The American Heart Association notes BMI should be used alongside other measures of adiposity 1
Clinical Caveat
The 2023 American Medical Association policy clarifies that BMI has limitations in clinical settings and historical roots in racist exclusion, recommending it be used with other valid risk measures 1. Despite being proposed as a "vital sign" in some literature 2, BMI remains fundamentally an anthropometric screening tool rather than a true vital sign.