The World Health Organization declared Covid-19 a global pandemic on March 11, 2020 — two years ago. Since then, just under 1 million people have died from the virus in the United States alone, with global numbers passing 6 million on Monday, March 2.

“It’s been two years since the worst pandemic and public health crisis in 100 years started,” said Kaiser Permanente Dr. Stephen Parodi. “Almost 1 million people in the United States have died from Covid-19, and many continue to fall ill from the illness.”

Two years after the onset of the pandemic, however, a potentially newly discovered side effect may be appearing.

In addition to the difficulty that Covid-19 already brings, roughly 15% of patients also develop a condition called “Long Covid,” according to Parodi.

Also known as post-Covid conditions, it describes Covid-19 related symptoms that a person may still continue to feel weeks or even months after the patient tests negative for the disease.

Symptoms of Long Covid include similar symptoms to the virus itself, including shortness of breath, cough, fatigue, and difficulty thinking or concentrating (sometimes referred to as “brain fog”) among other symptoms.

“People with long-term Covid -19 may need a combination of treatments,” Parodi said. These treatments include medications, counseling, and treatment for issues, both mentally and physically.

Parodi said that despite Long Covid becoming more common in past Covid -19 patients, the science is still new to researchers.

“It’s still not known why some patients develop long-term Covid -19 and others don’t,” Parodi said. “Although it appears more likely in patients who have had severe Covid -19 illness, it can also occur in those who had mild or moderate cases.”

He went on to say that despite the trends, the symptoms can potentially appear in any individual who had Covid -19, regardless of age.

“Long-term Covid -19 can also make underlying health conditions worse, such as asthma, diabetes, or other medical conditions,” Parodi added. “Talk with your doctor if you have ongoing symptoms.”

Parents who are pregnant or breastfeeding should also talk with their doctor if they are showing signs of Long Covid.

“We can’t predict who may be at risk for long-term Covid -19,” Parodi added. “Some early studies of long-term patients suggest that about 1 in 10 adults who get Covid -19 may be affected.”

He added that Long Covid can affect multiple body systems, including “our brain, our nervous system, heart, lungs, and other organs as well.”

Parodi reiterated the importance of getting vaccinated, adding that being vaccinated helps protect against developing Long Covid.

“I would not be surprised if Covid -19 vaccination becomes a part of either a near-term or a far-term vaccination series,” Parodi said.