COVID-19 is a respiratory infection caused by the SARS-CoV-2 virus. Illness ranges from mild symptoms to severe pneumonia and complications. Vaccination and previous infection reduce the risk of severe disease, but infection and transmission can still occur.
Possible symptoms
- Fever or chills
- Cough, sore throat or a blocked or runny nose
- Shortness of breath
- Tiredness, headache or muscle aches
- Loss or change in smell or taste
- Reduced appetite, nausea, vomiting or diarrhoea
Symptoms overlap with influenza, the common cold and other infections. A test may be useful when the result will affect treatment, contact with a vulnerable person or local public-health guidance.
Care and treatment
Most mild infections can be managed with rest, fluids and appropriate medicine for pain or fever. People at highest risk of severe illness may be eligible for antiviral treatment, which must be started early. Eligibility and access differ by country, so contact a local healthcare service promptly after symptoms begin.
Seek individual advice before taking antiviral medicine because important interactions can occur with other medicines. Antibiotics do not treat COVID-19 unless a bacterial infection is also present.
Reducing spread
Stay away from others while feverish or too unwell for normal activities. Improve indoor ventilation, cover coughs and sneezes, wash hands and consider a well-fitting mask in crowded indoor settings or around people at high risk. Follow current local guidance because testing and isolation recommendations can change.
Long COVID
Some people have fatigue, breathlessness, cognitive problems, altered smell or other symptoms that continue or develop after the initial infection. Persistent symptoms should be assessed, especially when they affect daily life or are worsening.
When to seek urgent help
Get urgent medical advice if symptoms are worsening or a high-risk person develops COVID-19. Call emergency services for severe breathing difficulty, inability to speak short sentences at rest, sudden chest pain, blue or grey lips, confusion, collapse, a seizure or coughing up blood.
Sources
Reviewed: 28 August 2026