What are the symptoms of pneumonia?

Symptoms of Pneumonia

Pneumonia typically presents with cough and difficulty breathing, accompanied by fever, tachypnea, and chest indrawing, though the specific symptom constellation varies significantly by age group and pathogen. 1

Core Respiratory Symptoms

The primary respiratory symptoms that should prompt evaluation for pneumonia include:

• Cough (new or increased) is the most common presenting symptom across all age groups 1, 2
• Difficulty breathing or dyspnea (reported or observed) is a critical symptom, often more diagnostically useful than isolated cough in older children 1
• Tachypnea (rapid breathing) is a key clinical sign, particularly in children under 5 years, with age-specific thresholds defining abnormal rates 1
• Chest indrawing (recession) indicates increased work of breathing and suggests more severe disease 1

Systemic Symptoms

Beyond respiratory manifestations, pneumonia commonly presents with:

• Fever (>38.5°C in children, >38°C in adults) is a common but nonspecific finding 1, 3, 2
• Fatigue and malaise are frequently reported, particularly in bacterial pneumonia 3, 4
• Loss of appetite is common across age groups 3
• Pleuritic chest pain occurs when pleural surfaces are involved 3

Age-Specific Presentations

Children and Infants

Pediatric pneumonia presentations differ substantially from adults:

• Fever >38.5°C combined with chest recession and respiratory rate >50/min strongly suggests bacterial pneumonia in children under 3 years 1
• Inability to drink, vomiting everything, convulsions, lethargy, or unconsciousness represent WHO-defined general danger signs indicating severe pneumonia 1
• Severe respiratory distress signs include head nodding, persistent nasal flaring, grunting, stridor while calm, tracheal tugging, intercostal retractions, and pronounced lower chest wall indrawing 1

Elderly and Atypical Presentations

Older adults may present without classic symptoms:

• Headache, nausea, and abdominal pain can replace typical respiratory symptoms in children and elderly patients 3
• Absence of fever or prominent respiratory symptoms may occur in elderly patients, making diagnosis more challenging 5
• Confusion or altered mental status can be a presenting feature in older adults 6

Physical Examination Findings

Key auscultatory findings include:

• Inspiratory crackles are present in approximately 81% of pneumonia cases, representing the most common physical finding 7
• Diminished breath sounds over affected lung regions indicate consolidation and reduced air movement 7
• Bronchial breathing may be present but typically not at symptom onset 1

Important caveat: Fever and tachycardia are common but have low specificity for pneumonia 1

Pathogen-Specific Symptom Patterns

Bacterial Pneumonia (Pneumococcal)

• Fever and tachypnea typically precede cough, as alveolar involvement initially produces minimal cough until debris reaches airways 1
• Toxic appearance ("looks sick") with fever and breathlessness is characteristic 1

Mycoplasma Pneumonia

• Fever, arthralgia, headache, cough, and crackles in school-aged children suggest mycoplasma infection 1, 4
• Wheezing occurs in 30% of mycoplasma cases, more common in older children 1
• Symptoms suggesting primary atypical pneumonia including cough, fever, chills, headache, and malaise with normal or slightly elevated white blood cell count 4

Viral Pneumonia

• Accessory symptoms such as anosmia (loss of smell) or ageusia (loss of taste) with respiratory symptoms suggest COVID-19 8
• Clinical presentation ranges from mild to severe pneumonitis complicated by respiratory failure in severe cases 8

Critical Warning Signs

If wheeze is present in a preschool child, primary bacterial pneumonia is very unlikely 1

Severe pneumonia indicators requiring immediate attention include:

• Hypoxemia (SpO₂ <93% or altitude-adjusted) 1, 6
• Leukopenia (WBC <4,000 cells/mm³) indicates overwhelmed immune response and higher mortality risk 6, 2
• Respiratory rate ≥30 breaths/min in adults 6
• Multilobar infiltrates on imaging 6
• Hypotension requiring aggressive fluid resuscitation 6

Occult Pneumonia Without Typical Symptoms

Pneumonia can rarely present without chest symptoms:

• In febrile children >3 months with temperature >39°C and marked leukocytosis, occult pneumonia may be present in up to 26% despite absent respiratory symptoms 5
• In febrile infants <3 months without respiratory symptoms, radiographic pneumonia prevalence is <3% 5
• If all clinical signs (respiratory rate, auscultation, work of breathing) are negative, chest radiographic findings are unlikely to be positive 5