What is COVID-19?
COVID-19 is an infectious illness caused by a coronavirus. It primarily affects the respiratory system — the nose, throat and lungs — but can affect other parts of the body too. Since emerging, the virus has become one of the common respiratory infections that circulate, particularly in colder months, alongside colds and flu. Most people who catch it have a mild to moderate illness and recover without needing hospital care.
The illness varies widely from person to person. Some have no symptoms at all, many have a mild, cold-like illness, and a smaller number become more seriously unwell, particularly those who are older or have certain health conditions. Because its symptoms overlap with colds and flu, testing is often the only reliable way to know which infection a person has. Understanding the symptoms, how it spreads, and when to seek help allows people to look after themselves and protect others.
Symptoms
COVID-19 symptoms can vary and overlap with other respiratory infections. They may be mild or more pronounced, and not everyone has all of them. Common symptoms include:
- •A high temperature or feeling feverish, and chills
- •A new, continuous cough
- •Loss or change to sense of smell or taste
- •Shortness of breath
- •Tiredness or fatigue
- •Sore throat, headache, and aches
- •A blocked or runny nose, and sometimes nausea or diarrhoea
How it spreads
COVID-19 spreads mainly from person to person through respiratory droplets and smaller particles released when an infected person breathes, talks, coughs or sneezes. People nearby can breathe these in, and in poorly ventilated indoor spaces the particles can linger in the air. It can also spread, less commonly, by touching a contaminated surface and then the face.
A person can spread the virus before they feel unwell and while they have symptoms, which is part of why it spreads easily. Good ventilation, covering coughs and sneezes, hand hygiene, and staying away from others when unwell all reduce transmission. Because guidance on isolation and precautions has changed over time and varies by place, it is worth checking current local advice during periods of high spread.
Treatment and recovery
Most people with COVID-19 recover at home with rest and self-care, as antibiotics do not work against the virus. The focus is on easing symptoms: resting, drinking plenty of fluids, and using paracetamol or ibuprofen as directed to reduce fever and aches. A pharmacist can advise on remedies for a cough or sore throat. Most people start to feel better within a week or two, though a cough and tiredness can linger longer.
For people at higher risk of becoming seriously unwell, specific antiviral or other treatments are sometimes available and work best when started early, so those in higher-risk groups should seek advice promptly if they test positive. Vaccination, where recommended and available, reduces the risk of serious illness, and current local guidance is the best source for who is eligible. Throughout recovery, it helps to watch for any warning signs that warrant medical attention rather than assuming all cases stay mild.
Higher-risk groups and long COVID
While most people recover fully, some are at higher risk of serious illness from COVID-19. These include older adults, people with long-term conditions such as heart or lung disease, diabetes or a weakened immune system, and, to some degree, those who are pregnant. For these groups, more caution, prompt advice if symptoms develop, and staying up to date with recommended vaccination are all worthwhile.
A minority of people develop symptoms that persist for weeks or months after the initial infection, often called long COVID or post-COVID syndrome. Symptoms can include ongoing fatigue, breathlessness, brain fog, and others, and can affect people regardless of how mild their initial illness was. If symptoms persist well beyond the expected recovery period and affect daily life, it is worth speaking to a doctor, who can assess them and advise on management and support.
Recognising warning signs helps everyone act when needed. Severe breathlessness, chest pain, blue lips, confusion, or being unable to stay awake are emergencies. For most people, though, COVID-19 is a self-limiting respiratory illness managed at home, and knowing both the reassuring norm and the warning signs allows a calm, informed response.
Testing and knowing what you have
Because COVID-19 shares so many symptoms with colds and flu, it is often impossible to know which infection you have from symptoms alone. Testing is the reliable way to confirm COVID-19, and tests are widely available in many places, including rapid tests that can be done at home and laboratory tests. Whether testing is recommended, and what to do with the result, depends on current local guidance, your circumstances, and whether you are in a higher-risk group.
Knowing whether you have COVID-19 can matter for a few reasons: it may affect whether specific early treatments are appropriate (particularly for higher-risk people), how you protect others around you, and what local guidance advises about isolation or precautions. For many otherwise healthy people with mild symptoms, the practical management — rest, fluids and symptom relief — is similar regardless of which respiratory virus is responsible.
If you are in a higher-risk group, testing promptly when symptoms develop is especially worthwhile, as some treatments work best when started early. For everyone, following current local guidance on testing and what to do with a positive result is the best approach, since recommendations have evolved over time and continue to vary by place and situation.