What are the signs of COVID-19 (Coronavirus disease 2019)?

Signs and Symptoms of COVID-19

The most common signs and symptoms of COVID-19 include fever (92.8%), cough (69.8%), fatigue, and notably gustatory (88.8%) and olfactory (85.6%) dysfunctions, which are stronger predictors of COVID-19 diagnosis than self-reported fever. 1

Common Symptoms by System

Respiratory Symptoms

• Cough (69.8%)
• Dyspnea/shortness of breath (34.5%)
• Sore throat (5.1%)
• Rhinorrhea (4.0%)
• Pharyngalgia (17.4%)

Systemic Symptoms

• Fever (92.8%)
• Fatigue/malaise
• Myalgia/muscle pain (27.7%)
• Headache (7.2%)

Sensory Disturbances

• Anosmia (loss of smell) (85.6%)
• Ageusia (loss of taste) (88.8%)

Gastrointestinal Symptoms

• Nausea and vomiting
• Diarrhea (6.1%)
• Abdominal pain
• Anorexia/poor appetite 2

Disease Progression and Severity

COVID-19 typically progresses through distinct stages:

1. Early Stage (0-4 days): Initial symptoms appear with subpleural ground glass opacities in lower lung lobes
2. Progressive Stage (5-8 days): Bilateral distribution of infection with diffuse ground glass opacities
3. Peak Stage (9-13 days): Dense consolidation, crazy-paving pattern, and residual parenchymal bands
4. Absorption Stage (≥14 days): Gradual resolution and signs of recovery 2

Disease severity can be classified as:

• Mild (81%): Non-pneumonia or mild pneumonia
• Severe (14%): Dyspnea, respiratory frequency ≥30/min, blood oxygen saturation ≤93%, partial pressure of arterial oxygen to fraction of inspired oxygen ratio <300, and/or lung infiltrates >50% within 24-48 hours
• Critical (5%): Respiratory failure, septic shock, and/or multiple organ dysfunction or failure 2, 1

Special Populations

Children

• May present with fever, fatigue, cough, nasal congestion, runny nose, expectoration, diarrhea, and headache
• As disease progresses: dyspnea, cyanosis, malaise, restlessness, poor feeding, reduced activity
• Severe cases: respiratory failure, septic shock, metabolic acidosis, bleeding, and coagulation dysfunction
• Up to 45% of children may be asymptomatic 2

Atypical Presentations

• Neurological manifestations: slurred speech, dizziness, weakness, encephalopathy 3
• Dermatological manifestations: erythematous rashes, urticaria, chicken pox-like lesions 4
• Cardiovascular manifestations: arrhythmias, myocardial injury 2
• Renal manifestations: proteinuria, hematuria, elevated BUN and creatinine 4

Clinical Pearls and Pitfalls

• Important pitfall: Asymptomatic carriers can still transmit the virus, with viral loads similar to symptomatic patients 2
• Red flag symptoms: Fever, myalgia/arthralgia, fatigue, and headache have specificities above 90%, substantially increasing the likelihood of COVID-19 when present 5
• Key diagnostic consideration: Patients may present with non-respiratory symptoms only, particularly gastrointestinal or neurological manifestations, without fever or respiratory symptoms 3
• Incubation period: Ranges from 1-14 days (average 5.2 days) from infection to symptom onset 2
• Transmission risk: An infected individual may spread the disease to approximately 2.2 people on average 2

Early recognition of these diverse signs and symptoms is crucial for prompt diagnosis, isolation, and treatment to reduce morbidity, mortality, and disease transmission.