Nearly 9 million people say they are still dealing with it.
LOS ANGELES (KABC) -- Millions of Americans say they have had long COVID, and many say they're still battling it.
At the same time, scientists are making progress in creating a blood test to detect this condition. New data from the Centers for Disease Control and Prevention reveals the wide reach of long COVID on Americans.
The National Health Survey found nearly 7% of adults, roughly 18 million people, reported ever having long-term symptoms and nearly 9 million say they are still dealing with it. Besides the brain fog and fatigue, long COVID can present a constellation of symptoms.
"A high heart rate, chest pain, shortness of breath and an inability to do any work," said Dr. Purvi Parwani, who treats patients at the COVID Heart Clinic at Loma Linda University Health.
She said these symptoms could persist for at least four weeks after being infected and can last months or years.
The data shows it affects nearly twice as many women than men. Parwani said she sees more women experience dizziness and faintness.
"I don't think we understand fully what the gender difference is and why that exists at the mechanistic level," she said. "In our clinical experience, we do see these symptoms more in women than in men.
There isn't a test that can confirm long COVID.
But in a new Journal Nature paper, scientists at Mount Sinai and Yale discovered certain immune markers and cortisol levels were different in people who have long COVID compared to those who don't.
Much more research is needed, but experts believe this could be the first step toward blood tests that could help confirm a long COVID diagnosis.
"I do think it's a promising first step where we can apply this knowledge into our clinical practice, and perhaps give some answers to our patients," Parwani said.
Earlier this year, the Biden Administration announced it was forming a new Office of Long COVID Research and Practice to study the condition and help those who have been diagnosed with it.