Up to one in five American adults who reported having COVID-19 in the past are still having symptoms of long COVID, and approximately 1 million Americans have been forced to leave the labor market because of the condition, according to a hearing held by the Select Subcommittee on the Coronavirus Crisis on Tuesday. 

Long COVID, or post COVID-19 condition, refers collectively to the constellation of long-term symptoms that some people experience after they have had COVID-19. Some people develop a variety of mid and long term effects like fatigue, breathlessness and cognitive dysfunction, the World Health Organization (WHO) defined. 

Post COVID-19 condition can affect a person's ability to perform daily activities such as work or household chores, according to the WHO. 

Dr Monica Verduzco-Gutierrez, a doctor who specializes in physical medicine and rehabilitation, said during the hearing that many of her patients have overlapping symptoms with those seen after brain disease: dizziness, memory loss, concentration problems, insomnia, headaches, tremors, anxiety, PTSD and suicidal thoughts. 

In a written testimony provided before the hearing, Verduzco-Gutierrez said that she has treated cancer patients who say long COVID is "100 times worse than their cancer fatigue ever was."

"They lost their job and healthcare insurance, or they are so disabled they can't get out of bed. This is a public health crisis," she said. 

An estimated 28 million Americans have had long COVID at some point, though many have recovered. Around 16 million Americans are estimated to currently be suffering from long COVID, according to Katie Bach, a nonresident senior fellow at the Brookings Institute. 

She estimates that 4 million full-time workers may now have a reduced ability to work. 

The number of confirmed COVID-19 cases in the U.S. has surpassed 91 million, according to data from Johns Hopkins University on Wednesday. 

The BA.5 subvariant of Omicron was estimated to make up 77.9 percent of the circulating coronavirus variants in the United States, the U.S. Centers for Disease Control and Prevention said on Tuesday.