What are the possible causes of symptoms in an adult or geriatric patient with a complex medical history?

Possible Causes of Symptoms in Adults and Geriatric Patients with Complex Medical History

In adults and geriatric patients with complex medical histories presenting with multiple persistent symptoms, the most likely causes include chronic multisymptom illness (CMI), multimorbidity-related complications, medication adverse effects, acute infections (particularly urinary tract infections), cardiovascular events, metabolic derangements, and geriatric syndromes such as delirium, frailty, and cognitive impairment. 1, 2

Primary Diagnostic Considerations

Chronic Multisymptom Illness (CMI)

• CMI is characterized by multiple, persistent symptoms (fatigue, headache, arthralgias, myalgias, concentration problems, gastrointestinal disorders) across more than one body system, present or frequently recurring for more than 6 months, severe enough to interfere with daily functioning. 1
• This condition affects quality of life substantially and requires a holistic assessment approach rather than single-disease focused evaluation. 1

Multimorbidity and Coexisting Chronic Illnesses

• More than 50% of older adults have three or more chronic diseases, with distinctive cumulative effects for each individual, associated with higher rates of death, disability, adverse effects, institutionalization, and poorer quality of life. 1
• Common coexisting conditions include hypertension, arthritis, heart disease, pulmonary disease, cancer, diabetes, history of stroke, congestive heart failure, depression, emphysema, falls, incontinence, and stage 3 or worse chronic kidney disease. 1
• Eighty percent of geriatric patients have at least one chronic disease, and when combined with frailty, this results in more vulnerability to stress. 1

Acute Infection Superimposed on Chronic Conditions

• Evaluate immediately for systemic infection by assessing fever, rigors or shaking chills, clear-cut delirium, hemodynamic instability (hypotension and tachycardia), as these symptoms are associated with increased risk of sepsis. 2
• Assess for focal genitourinary symptoms including recent-onset dysuria, new costovertebral angle pain or tenderness, urinary frequency, urgency, or new incontinence, as these indicate possible urinary tract infection. 2
• Urinary tract infections are particularly common in elderly patients and can present atypically with confusion or falls rather than classic urinary symptoms. 2

Cardiovascular Events

• Cardiogenic shock in older adults presents as a continuum ranging from preshock to refractory shock states, involving cycles of ischemia, vascular instability, inflammation, and potential for multiorgan dysfunction. 1
• Older adults with cardiovascular disease may present with atypical symptoms including fatigue, confusion, or functional decline rather than classic chest pain. 1
• Older adults tend to be more prevalent in the cardiorenal phenotype, exhibiting greater congestion, cardiorenal dysfunction, and higher comorbidity burdens. 1

Metabolic and Endocrine Derangements

• In diabetic patients, poorly controlled diabetes may cause acute complications including dehydration, poor wound healing, and hyperglycemic hyperosmolar coma. 1
• Hypoglycemia is a significant risk in older adults with diabetes, particularly those with complex/intermediate health status or very complex/poor health. 1
• Electrolyte abnormalities, renal dysfunction, and glucose dysregulation commonly contribute to symptom burden. 2

Geriatric Syndromes

• Older adults with diabetes and other chronic conditions are at greater risk for several common geriatric syndromes including polypharmacy, depression, cognitive impairment, urinary incontinence, injurious falls, and persistent pain. 1
• Delirium is a critical consideration, as delirious patients treated for asymptomatic bacteriuria had worse functional outcomes and increased C. difficile infection risk. 2
• Frailty significantly impacts outcomes and should be assessed rather than relying solely on chronological age. 1

Medication-Related Adverse Effects

• Polypharmacy is common in older adults with multimorbidity and increases risk of adverse drug events, drug-drug interactions, and medication-related symptoms. 1
• Donepezil and other cholinesterase inhibitors can cause abdominal pain, agitation, aggression, confusion, hallucinations, nausea, vomiting, bradycardia, and other adverse effects. 3
• Special care is required in prescribing and monitoring pharmacological therapy in older adults, with cost being a significant factor. 1

Neurological Causes

• Cognitive disorders including mild cognitive impairment and dementia should be considered when patients present with reported cognitive symptoms, unexplained decline in instrumental activities of daily living, missed appointments, difficulty remembering or following instructions, decrease in self-care, or new onset later-life behavioral changes including depression or anxiety. 1
• Vascular cognitive impairment may present with multiple symptoms across body systems. 1

Critical Assessment Approach

Initial Evaluation Elements

• Obtain comprehensive medical history including military/deployment history if applicable, conduct psychosocial assessment including psychological trauma history, and perform thorough physical examination. 1
• Consider diagnostic studies only for rule-out of alternative diagnoses; avoid tests with limited additional benefit. 1
• Obtain complete metabolic panel to assess electrolytes, renal function, and glucose control. 2
• Obtain urinalysis with culture before starting antibiotics if infection is suspected. 2
• Obtain blood cultures if fever or systemic signs are present. 2

Key Clinical Pitfalls to Avoid

• Do not assume all mental status changes are from urinary tract infection—not all confusion in elderly patients with bacteriuria represents true infection. 2
• Do not rely solely on chronological age for clinical decision-making; assess individual patient characteristics including presence of geriatric conditions such as multimorbidity, polypharmacy, cognitive decline, delirium, and frailty. 1
• Do not apply single-disease clinical practice guidelines rigidly to patients with multimorbidity, as CPG-based care may be cumulatively impractical, irrelevant, or even harmful. 1
• Do not delay antibiotics if true infection is present, as untreated UTI can progress to urosepsis, particularly in elderly patients with multiple comorbidities. 2

Risk Stratification Based on Health Status

For older adults with diabetes (applicable framework for other chronic conditions): 1

• Healthy patients (few coexisting chronic illnesses, intact cognitive and functional status): Longer remaining life expectancy warrants more aggressive management of cardiovascular risk factors and tighter glycemic control (A1C <7.5%). 1

• Complex/intermediate patients (multiple coexisting chronic illnesses or ≥1 instrumental ADL impairments or mild-to-moderate cognitive impairment): Intermediate remaining life expectancy with high treatment burden and hypoglycemia vulnerability requires less aggressive targets (A1C <8.0%). 1

• Very complex/poor health patients (long-term care or end-stage chronic illnesses or moderate-to-severe cognitive impairment or ≥1 ADL dependencies): Limited remaining life expectancy makes benefit uncertain; use looser targets (A1C <8.5%) to avoid acute complications while minimizing treatment burden. 1

Treatment Implications

Holistic Management Approach

• Using a whole/holistic health approach, identify individual treatment goals (return to work, improved quality of life, resumption of recreational activities) through shared decision-making discussion and shared goal setting. 1
• Maximize use of nonpharmacologic therapies including cognitive-behavioral therapy, complementary and integrative health interventions, and aerobic exercise. 1
• Consider yoga or tai chi for patients with CMI and symptoms consistent with fibromyalgia syndrome, and manual acupuncture as part of management. 1

Monitoring and Follow-up

• Maintain continuity and caring relationship through in-person or virtual modalities, provide education for improved health literacy and whole/holistic health self-care, and engage families/caregiver/support person if available. 1
• Reassess for clinical improvement, culture results, renal function, and alternative diagnoses within 48-72 hours when treating suspected infection. 2
• Based on patient needs, consider referral to case manager and establish interprofessional care team. 1