1.1.1 Health Assessment

Health assessment is the systematic, comprehensive process of collecting, analyzing, and interpreting data about an individual's physical, psychological, social, and functional status to establish a baseline of health, identify actual and potential health problems, and guide clinical decision-making, preventive interventions, and therapeutic planning. It is the foundational act of every clinical encounter — the structured inquiry through which a clinician moves from the patient's subjective experience of health or illness to an objective, evidence-based understanding of their condition. Health assessment is not a single act but a dynamic, iterative process that spans the continuum from health promotion and disease prevention to acute care and rehabilitation.

The Purposes of Health Assessment

Health assessment serves multiple simultaneous purposes that extend well beyond the identification of disease.

Health assessment establishes a documented baseline against which future changes — improvement, deterioration, or stability — can be measured. It identifies existing health problems requiring treatment, risk factors predisposing the individual to future disease, and protective factors that can be reinforced. It generates the data required to formulate nursing diagnoses, medical diagnoses, and interprofessional care plans. It evaluates the effectiveness of interventions already underway and detects complications or adverse effects. And it creates the therapeutic relationship — the foundation of trust and communication — within which all subsequent care takes place.

Types of Health Assessment

Health assessments are classified by their scope, timing, and purpose, each suited to a different clinical context.

A comprehensive assessment collects a complete health history and performs a full systematic physical examination, incorporating functional, nutritional, psychosocial, and risk factor screening. It is the standard for new patient encounters and periodic health reviews.

A focused assessment concentrates on a specific problem, symptom, or body system relevant to the presenting complaint — a patient with chest pain receives a cardiovascular and respiratory focused assessment rather than a full systematic examination.

An emergency assessment applies the structured ABCDE approach (Airway, Breathing, Circulation, Disability, Exposure) to rapidly identify and simultaneously manage life-threatening abnormalities, prioritizing survival over comprehensive data collection.

An ongoing assessment is the continuous monitoring of a patient's status throughout care — vital sign surveillance, wound assessment, neurological checks, or medication response monitoring — that detects change and informs real-time clinical decisions.

The Health History

The health history is the cornerstone of health assessment, providing approximately 70–80% of the information needed to reach a diagnosis before any physical examination or investigation is performed. It is obtained through structured therapeutic communication — purposeful, patient-centered conversation guided by open-ended questions, active listening, and empathic response.

The OLDCARTS Framework

The history of present illness is structured using validated mnemonics to ensure all clinically relevant dimensions of a symptom are captured. OLDCARTS is the most widely applied.

Systematic application of OLDCARTS ensures no dimension of the symptom is overlooked and generates the clinical narrative that drives the differential diagnosis.

Vital Signs

Vital signs are the four — and in expanded clinical practice, five or six — fundamental physiological parameters that provide an immediate, objective window into a patient's cardiorespiratory and neurological status. They are the most frequently repeated element of health assessment and serve as the primary early warning system for clinical deterioration.

Temperature reflects the balance between heat production and dissipation. Fever (pyrexia, temperature >38°C) indicates infection, inflammation, or systemic illness. Hypothermia (<35°C) reflects exposure, septic shock, or severe metabolic disturbance. The method of measurement — oral, axillary, tympanic, rectal, or temporal — affects the reading, with rectal being most accurate for core temperature.

Heart rate is assessed for rate (bradycardia <60, tachycardia >100), rhythm (regular, irregularly irregular in atrial fibrillation), volume (full, weak, thready), and character (bounding in aortic regurgitation, collapsing in sepsis). The radial pulse is the standard site; central pulses (carotid, femoral) are assessed in emergency states.

Respiratory rate is the most sensitive early indicator of physiological deterioration and the most frequently underrecorded vital sign. An adult respiratory rate above 20 breaths/minute is a key early warning sign of acute illness regardless of aetiology.

Blood pressure is measured bilaterally at first encounter. A difference of >15 mmHg between arms suggests subclavian stenosis or aortic coarctation. Orthostatic (postural) blood pressure measurement — comparing supine, sitting, and standing values — identifies autonomic dysfunction and volume depletion.

Oxygen saturation (SpO₂) measured by pulse oximetry provides a continuous, non-invasive estimate of haemoglobin oxygen saturation. Values below 94% in a previously healthy adult indicate hypoxaemia requiring urgent assessment.

Pain is now widely recognized as the fifth vital sign, assessed using validated tools including the numerical rating scale (0–10), visual analogue scale, Wong-Baker FACES scale (pediatric and non-verbal), and the CPOT (Critical Care Pain Observation Tool) for sedated patients.

Physical Examination

The physical examination is the systematic, hands-on evaluation of the body using four classical techniques applied in a consistent sequence to every body region and system.

Inspection is always performed first and requires adequate exposure, lighting, and a systematic gaze — noting colour, contour, symmetry, movement, surface characteristics, and any visible abnormalities. It begins from the moment the patient is first observed.

Palpation uses the hands to detect temperature, texture, moisture, masses, organ size, pulsations, tenderness, crepitus, and rigidity. Light palpation (1–2 cm depression) precedes deep palpation (4–5 cm), and areas of reported pain are examined last.

Percussion produces sounds by tapping the body surface, generating vibrations that characterize the density of underlying tissue. Resonance indicates air-filled tissue (healthy lung); dullness indicates solid tissue or fluid (hepatic dullness, pleural effusion); tympany indicates a hollow air-filled viscus (stomach, bowel).

Auscultation is performed last (except in abdominal examination, where it precedes percussion to avoid altering bowel sounds). It evaluates heart sounds (S1, S2, and the presence of murmurs, gallops, or rubs), breath sounds (vesicular, bronchial, adventitious — crackles, wheeze, pleural rub), and bowel sounds.

Systems-Based Physical Examination

The physical examination proceeds systematically through each body system, generating objective findings that corroborate, refute, or refine the diagnostic hypotheses generated by the health history.

Cardiovascular System

Assessment includes inspection of the precordium for visible pulsations and deformities, palpation of the apex beat (normally 5th intercostal space, mid-clavicular line), assessment of the jugular venous pressure (JVP) as a non-invasive measure of right atrial pressure, and auscultation of heart sounds in all four valve areas. Peripheral assessment includes pulse character, peripheral perfusion (capillary refill, skin temperature, colour), and inspection for peripheral oedema, clubbing, and cyanosis.

Respiratory System

Assessment includes respiratory rate, pattern, and effort; chest wall symmetry and excursion; tracheal position; percussion — comparing resonance bilaterally and detecting areas of dullness (consolidation, effusion) or hyper-resonance (pneumothorax, emphysema); and auscultation of breath sounds and added sounds throughout all lung zones.

Abdominal System

The abdomen is examined in the supine position with the patient relaxed. Inspection evaluates distension, visible peristalsis, hernias, scars, and skin changes. Auscultation precedes percussion and palpation to avoid altering bowel motility. Percussion maps liver size, detects splenomegaly, and identifies free fluid (shifting dullness, fluid thrill). Palpation assesses tenderness, guarding, rigidity, rebound (peritoneal irritation), and organ enlargement.

Neurological System

A structured neurological examination assesses mental status (orientation, attention, memory, language), cranial nerves I–XII, motor system (tone, power, coordination), sensory system (light touch, pain, proprioception, vibration), reflexes (deep tendon, plantar), and cerebellar function (gait, heel-shin, finger-nose). The Glasgow Coma Scale (GCS) quantifies level of consciousness through eye opening, verbal response, and motor response, producing a score of 3–15.

Musculoskeletal System

Assessment evaluates posture and gait, joint inspection (swelling, deformity, erythema), range of motion (active and passive), muscle strength (graded 0–5 on the Medical Research Council scale), and special tests for specific structures (e.g. Lachman test for anterior cruciate ligament integrity, McMurray test for meniscal pathology).

Functional Assessment

Functional assessment evaluates a person's ability to perform the practical activities of daily life — a dimension of health that is not captured by diagnosis or physiological measurement alone but that profoundly determines quality of life, independence, and care needs.

Activities of Daily Living (ADLs) — the Katz ADL Scale — assess six basic self-care tasks: bathing, dressing, toileting, transferring, continence, and feeding. Dependence in these tasks indicates significant functional impairment requiring supportive care.

Instrumental Activities of Daily Living (IADLs) — the Lawton IADL Scale — assess higher-level functions: managing finances, preparing meals, shopping, housekeeping, using transportation, managing medications, and using the telephone. IADL impairment typically precedes ADL decline and may be the first functional indicator of cognitive deterioration.

Mental Health and Cognitive Assessment

Mental health assessment is an integral component of comprehensive health assessment, not a separate discipline reserved for psychiatric settings. It encompasses evaluation of mood, affect, cognition, perception, thought content and form, insight, and judgment.

Cognitive screening uses validated, brief tools to detect impairment requiring further neuropsychological evaluation. The Mini-Mental State Examination (MMSE) (maximum 30 points) and the Montreal Cognitive Assessment (MoCA) (maximum 30 points, more sensitive for mild cognitive impairment) assess orientation, registration, attention, recall, language, and visuospatial function. A MoCA score below 26 indicates possible cognitive impairment.

Depression screening uses validated instruments such as the PHQ-9 (Patient Health Questionnaire-9) — a nine-item scale aligned with DSM-5 criteria for major depressive disorder — or the Geriatric Depression Scale (GDS) for older adults. A PHQ-9 score ≥10 indicates moderate depression and warrants clinical intervention.

Anxiety screening uses the GAD-7 (Generalized Anxiety Disorder 7-item scale), with a score ≥10 indicating moderate anxiety requiring further assessment.

Risk Assessment and Screening Tools

Health assessment integrates validated structured risk assessment tools that quantify the probability of specific adverse outcomes and trigger preventive interventions.

The National Early Warning Score 2 (NEWS2) aggregates six physiological parameters into a composite score that determines the level of clinical response required — from routine monitoring (score 0–4) to emergency medical team activation (score ≥7). It is now mandated in many acute healthcare systems as the primary early warning tool.

Nutritional Assessment

Nutritional status is a determinant of recovery, immune function, wound healing, and medication response that is frequently underassessed in clinical settings. The ABCD method integrates anthropometric, biochemical, clinical, and dietary data. Anthropometric measures include BMI, mid-upper arm circumference (MUAC), and waist circumference. Biochemical markers include serum albumin, pre-albumin, C-reactive protein, full blood count, and specific micronutrient assays. Clinical signs include muscle wasting, peripheral oedema, and skin and hair changes. Dietary assessment quantifies intake through 24-hour recall, food frequency questionnaires, or dietary records.

Documentation and Communication

The findings of health assessment are recorded in structured clinical documentation — the medical or nursing record — that serves as a legal document, a communication tool across the multidisciplinary team, a baseline for monitoring, and an audit resource. Documentation follows the SOAP format (Subjective, Objective, Assessment, Plan) in problem-oriented records, or narrative or checklist formats in other systems.

Handover communication uses structured tools such as SBAR (Situation, Background, Assessment, Recommendation) to ensure critical assessment findings are conveyed accurately between clinicians at transitions of care — identified as a primary point of vulnerability for adverse events in healthcare.

Ethical and Cultural Dimensions

Health assessment is not a purely technical act — it occurs within a relational, ethical, and cultural context that must be consciously navigated. Informed consent requires that the patient understands the purpose and nature of the assessment and agrees to proceed. Confidentiality governs how assessment findings are documented, communicated, and stored. Cultural competence demands awareness of how cultural background, language, health beliefs, gender norms, and past experiences with healthcare systems influence the patient's communication, symptom expression, and engagement with assessment. The use of trained interpreters — not family members — is essential when language barriers exist, to ensure accuracy and preserve the patient's autonomy and dignity. A culturally humble approach — characterized by curiosity, respect, and the suspension of assumptions — is the foundation of valid and therapeutic health assessment across all populations.