First Symptoms of COVID-19
The most common initial symptoms of COVID-19 are fever (92.8%), cough (69.8%), and fatigue, with gustatory (88.8%) and olfactory (85.6%) dysfunctions being stronger predictors of COVID-19 diagnosis than self-reported fever. 1
Primary Symptoms by Frequency
Respiratory Symptoms:
- Dry cough (69.8%)
- Dyspnea/shortness of breath (34.5%)
- Sore throat (30%)
- Nasal congestion (28.3%)
- Nasal obstruction (26.7%)
- Sneezing (26.6%)
- Rhinorrhea/runny nose (20%)
Systemic Symptoms:
- Fever (92.8%)
- Fatigue/malaise
- Myalgia/muscle pain (27.7%)
- Headache (25%)
Sensory Symptoms:
- Gustatory dysfunction/taste loss (88.8%)
- Olfactory dysfunction/smell loss (85.6%)
Gastrointestinal Symptoms:
- Diarrhea (6.1%)
- Nausea/vomiting
- Abdominal pain
Symptom Onset and Progression
The incubation period for COVID-19 ranges from 1-14 days, with symptoms typically appearing around 5 days after exposure 1. The disease progression can be categorized into stages based on CT findings:
- Early stage (0-4 days): Initial symptoms appear, often starting with fever and dry cough
- Progressive stage (5-8 days): Symptoms may worsen with increasing respiratory involvement
- Peak stage (9-13 days): Maximum symptom severity
- Absorption stage (≥14 days): Gradual resolution of symptoms 1
Special Considerations
Predictive Value of Symptoms
Olfactory and gustatory dysfunctions are particularly strong predictors of COVID-19 diagnosis, even more so than fever 1. These symptoms should prompt consideration of COVID-19 testing, especially in high-prevalence settings.
Gastrointestinal Manifestations
While respiratory symptoms dominate, GI symptoms may precede respiratory symptoms by a few days in some patients 1. In outpatients with new-onset GI symptoms (nausea, vomiting, abdominal pain, diarrhea), monitoring for the development of other COVID-19 symptoms is recommended, particularly in high-prevalence settings 1.
Atypical Presentations
Some patients, particularly the elderly or those with comorbidities, may present with atypical symptoms or minimal respiratory complaints. Neurological manifestations like headache may be the presenting symptom in 6-10% of symptomatic COVID-19 patients 2.
Severity Classification
According to data from the Chinese Center for Disease Control and Prevention:
- 81% of cases are mild (non-pneumonia or mild pneumonia)
- 14% are severe (dyspnea, respiratory frequency ≥30/min, blood oxygen saturation ≤93%)
- 5% are critical (respiratory failure, septic shock, multiple organ dysfunction) 1
Clinical Pitfalls to Avoid
Don't dismiss mild symptoms: Many patients initially present with mild symptoms that may progress to more severe disease.
Don't overlook olfactory/gustatory symptoms: Loss of smell and taste are highly predictive of COVID-19 and may appear early in the disease course.
Don't ignore GI symptoms: Diarrhea, nausea, and abdominal pain may be the initial presenting symptoms in some patients before respiratory symptoms develop.
Don't wait for fever: While fever is common, some patients may not develop fever initially or at all.
Don't miss atypical presentations: Elderly patients or those with comorbidities may present with atypical symptoms or decompensation of underlying conditions.
When evaluating a patient with suspected COVID-19, a thorough assessment of all potential symptoms is essential, with particular attention to the constellation of fever, cough, and loss of taste or smell, which together are highly suggestive of COVID-19 infection.