While COVID-19 often includes a fever, many individuals contract the virus without this common symptom. Recognizing this helps ensure appropriate steps are taken for testing, symptom management, and preventing further spread.
Recognizing Other Symptoms
Even without a fever, COVID-19 can present with a wide array of other symptoms. A persistent cough, a sore throat, congestion, and a runny nose are common. Many individuals experience fatigue or generalized muscle and body aches.
A notable symptom for some is a new loss of taste or smell. Headaches are also frequently reported, as are gastrointestinal issues such as nausea, vomiting, or diarrhea. Less common manifestations can include chills, dizziness, or various types of skin rashes.
Symptoms typically appear within 2 to 14 days following exposure to the virus. Symptoms can be mild, making it difficult to differentiate COVID-19 from other respiratory illnesses like the common cold or flu. Despite mild symptoms, the virus remains contagious.
Reasons for No Fever
Several factors can explain why some individuals with COVID-19 do not develop a fever. Vaccination often leads to milder symptoms, including a reduced likelihood of fever, as the immune system is better prepared. Prior infection with SARS-CoV-2 also contributes to a milder response, as the immune system has some pre-existing memory.
Individual immune responses vary, with some people possessing specific genetic traits that help combat the virus more effectively. Newer SARS-CoV-2 variants, such as Omicron, cause fever less frequently than earlier variants. Children also tend to exhibit milder COVID-19 symptoms, including a lower incidence of fever, compared to adults.
Testing and Confirmation
Confirming a COVID-19 infection when fever is absent relies heavily on testing, as symptoms alone can be misleading. Two primary types of viral tests are available: rapid antigen tests and nucleic acid amplification tests (NAATs), which include PCR tests. Rapid antigen tests provide results quickly, usually within 15 to 30 minutes, and positive results are generally considered accurate.
However, antigen tests are less sensitive than NAATs, particularly when symptoms are not present or are very mild. A single negative antigen test may not rule out an infection, especially early in the course of the illness. The FDA suggests two negative antigen tests, taken 48 hours apart, for symptomatic individuals, and three negative tests for those without symptoms, to be more confident of no infection.
PCR tests are considered the “gold standard” for accuracy, detecting the virus’s genetic material, and are more likely to identify an infection. These tests typically involve a sample collected by a healthcare provider and sent to a lab, with results potentially taking up to three days. A PCR test can also be used to confirm a positive rapid antigen test result.
Managing COVID Without Fever
If you suspect or confirm a COVID-19 infection without a fever, taking immediate steps to prevent transmission and manage symptoms is important. Isolation is recommended to reduce spread, meaning you should stay home and avoid contact with others, particularly those at higher risk of severe illness. Current guidelines suggest isolating for at least five days from symptom onset or the day of a positive test if asymptomatic.
You are typically most contagious during these initial five days, and it is advisable to wear a well-fitting mask when around others indoors for a full 10 days after your symptoms started or your positive test date. Symptom management focuses on supportive care, including getting adequate rest and staying well-hydrated with water or electrolyte drinks. Over-the-counter medications like acetaminophen or ibuprofen can help relieve body aches and headaches.
Other remedies for specific symptoms include cough syrup, throat lozenges, or warm salt water gargles for a sore throat, and saline nasal drops or a humidifier for congestion. While most people recover at home, seek medical attention if symptoms worsen or become severe. Warning signs include trouble breathing, persistent chest pain or pressure, new confusion, inability to wake or stay awake, or bluish lips or face.