Understanding Long COVID & post-COVID complications

What is Long COVID?

Long COVID is a long-term (chronic) condition that occurs after COVID-19 infection and is present for at least 3 months. Long COVID includes a wide range of symptoms or conditions that may get better, get worse, or be ongoing.

You may hear the term Long COVID commonly used to describe ongoing, returning, or new symptoms that some people experience after a COVID-19 infection. These symptoms can begin while someone is still recovering or appear weeks or months later, and they may occur after mild or severe illness.

It’s important to know that Long COVID is not a single condition with a single cause. It’s a general term used to describe a range of possible symptoms.

Not all long-term health problems after COVID-19 are Long COVID. For example, some health problems that develop after COVID-19 may be related to the effects of a severe illness itself, such as lasting organ damage or new or worsening chronic conditions, rather than Long COVID.

Common symptoms and long-term health problems after COVID-19

Long-term health problems after COVID-19 can take many forms and are often grouped into two broad categories.

Ongoing or returning symptoms (often described as Long COVID) could include:

• Fatigue that makes everyday tasks harder than usual. Read more about Fatigue after COVID-19 explained: types and symptoms.
• Problems with thinking or concentration, such as forgetfulness or feeling mentally slow (often called ‘brain fog’). Read more about Brain health and cognitive function after COVID-19.
• Breathing problems, including feeling short of breath or having a lingering cough. Read more about Understanding persistent cough after COVID-19.
• Heart-related symptoms, such as chest discomfort or noticing your heart beating faster or irregularly. Read more about Heart health, blood pressure, & blood clot risks after COVID-19 and Understanding chest symptoms after COVID-19.
• Sleep issues, including difficulty falling asleep or waking frequently during the night.
• Changes in mood or emotional wellbeing, such as feeling anxious, low, or more irritable than before.

To learn more about the signs and symptoms of Long COVID-19, visit the U.S. Centers for Disease Control and Prevention.

People who have had severe COVID-19 may be more likely to experience long-term complications. These effects are more often seen in people who were hospitalized because of their COVID-19 infection, especially those who required care in an intensive care unit or had underlying health conditions before getting sick.

Other health complications after COVID-19 (not classified as Long COVID) may include:

• Ongoing respiratory issues, such as a lingering cough, reduced lung capacity or feeling short of breath
• Heart-related problems found during follow-up visits after recovery, sometimes linked to chest pain or tightness
• Effects on other organs, such as the kidneys, digestive system or liver
• New or worsening of chronic conditions, particularly in people with existing health issues

Why long-term health problems can occur after COVID-19

There is no single explanation for why some people experience long-term health problems after COVID-19. Researchers believe that it’s likely due to a combination of factors.

In some people, the immune system remains active longer than expected, which can lead to ongoing inflammation that affects different parts of the body. COVID-19 can also disrupt normal immune signaling and place stress on organs such as heart, lungs, blood vessels, and nervous system, especially after more severe illness.

Scientific understanding is evolving and awareness of post-COVID health problems has grown, with research continuing to improve care and support new approaches.

Who is at risk of long-term complications after COVID-19?

Anyone who has had COVID‑19 can experience long‑term health problems. However, some people are more likely to have ongoing effects.

People with underlying medical conditions or existing health conditions, such as lung or heart disease, diabetes, or a weakened immune system, are at higher risk of severe COVID‑19. You can read more about COVID-19 and chronic conditions.

Severe COVID-19 has been linked to a higher chance of ongoing health problems, including new or worsening chronic conditions. However, severe COVID-19 is not required to develop Long COVID. Even people who were never hospitalized can notice lasting health changes that affect their quality of life.

How is Long COVID diagnosed?

There is no single test that can diagnose whether ongoing health problems are related to a past COVID-19 infection. Instead, healthcare providers look at the wider picture, which may include:

• A person’s symptoms and how they have changed over time
• When symptoms started in relation to a confirmed or suspected COVID-19 infection
• A clinical assessment, which may involve physical exams or follow-up tests, depending on the symptoms involved

Because symptoms can change or fluctuate, healthcare providers often encourage people to keep track of what they are experiencing. This might include writing down when symptoms appear, how long they last, and how they impact everyday life.

Ongoing health problems after COVID-19 cannot be diagnosed on your own, so it’s important to speak with a healthcare provider for an accurate diagnosis.

What management and recovery support may look like

Support for long-term health problems after COVID-19 is usually tailored according to a person's individual experience and the symptoms they have. What works for one person may not work for another, and recovery can take different amounts of time.

Care may include support to:

• Help people manage day-to-day activities more comfortably
• Look at ways to reduce or cope with specific symptoms
• Support overall physical, mental, and emotional wellbeing

Some people notice steady improvement over time, while others have symptoms that come and go or improve more gradually. Understanding and talking about how symptoms affect your quality of life is an important part of ongoing care and follow-up.

How to reduce the risk of long-term health problems after COVID-19

Evidence suggests that people who did not become seriously ill with COVID-19 may be less likely to experience long-term health problems afterwards. However, there is no way to completely prevent the possibility of experiencing ongoing health issues after COVID-19.

What scientists understand about risk and prevention continues to develop, and a lot of progress has been made in understanding these long-term complications. Staying informed and talking with a healthcare professional about your personal health history and risk factors can help you make more informed decisions.

When to seek medical care about long-term health problems after COVID-19

It’s important to speak with a healthcare provider if you notice symptoms that:

• Do not go away or keep coming back
• Are new or getting worse
• Interfere with everyday activities, such as work, sleep, or taking care of yourself

You do not need to wait until symptoms become severe before seeking medical advice. A routine appointment can help clarify what may be happening and what next steps might be appropriate.

Preparing for your appointment by noting what symptoms you’re experiencing, when they started, and how they affect daily life, can support conversations with a healthcare provider. Learn more about  What to ask your healthcare provider if you have COVID-19.

Staying informed after COVID-19

Long-term health problems after COVID-19 are an area of ongoing research and learning. Experiences after COVID-19 can vary widely, and there isn’t a single experience that applies to everyone.

Taking the COVID-19 risk assessment can help you understand factors that may affect your risk. Staying informed and writing down changes in how you feel after COVID-19 can help you better understand your own health and feel more confident about next steps, if you need support.