• In addition to the increases in health-care costs that come with treating ongoing problems, there can be a big hit to income if symptoms are severe enough to rule out working.
• The National Institutes of Health has launched an initiative to research why some Covid survivors become long haulers.
• Exactly how many people end up in this category is hard to know.

It's been 10 months since Laura Crovo has felt entirely normal.

Since testing positive for Covid last April, the 41-year-old Marylander has yet to shake off all of her symptoms. And on top of battling them — mostly a racing heart (tachycardia), occasional fatigue and a lingering cough — she and her husband, parents of two children, are still paying off the thousands of dollars in debt that they racked up last year due to her persisting illness.

"I think you see a lot of people who are better in a week or two, and that's not necessarily the case for everyone else," said Crovo, who is far better than she was at her worst last year, when working was an impossibility.

As so-called Covid "long haulers" like Crovo navigate treatment options and the uncertainty that comes with long-lasting symptoms — i.e., when will they feel better? — they also have to deal with the cost. In addition to copays or coinsurance that may be required for a multitude of tests, doctor's appointments and treatments, there can be lost income if symptoms are severe enough to prevent working.

"Symptoms sometimes arise well after the time of infection, or they evolve over time and they may persist for months and can range from mild to actually quite incapacitating," said Dr. Anthony Fauci, White House chief medical advisor, in a briefing on Wednesday.

"The magnitude of the problem is not yet fully known," said Fauci. 

The National Institutes of Health this week launched the first phase of a research initiative to explore why some Covid survivors become long haulers.

Exactly how many people end up in this category is hard to know. One study suggests that about 10% of infected individuals will have symptoms that linger for weeks or months. Other research says the rate is more like 30%. Either way, there is little commonality among long haulers: some initially had mild cases of the virus, others had a more severe version. And, some had been hospitalized, while others had not.

More from Personal Finance:
Credit scores are rising amid the Covid crisis
Here's why you need to report cryptocurrency to IRS
How Social Security benefits are handled at death

Crovo falls among those who recovered at home. She had tested positive for Covid early last April, when little was known about the virus and treatment options were limited. So far in the U.S., the virus has sickened more than 28.4 million people and resulted in roughly 509,000 deaths.

Crovo's symptoms were typical: fever, cough, headache, fatigue, aches and pains, etc. However, they didn't disappear quickly as they do with many individuals who are infected.

With a fever that lasted 25 days, she was out of work for four weeks. Luckily, she said, her employer has been accommodating and supportive. She was given some paid sick leave, despite her having been there for less than a year. At another point, she worked only part-time for two weeks.

"At my sickest, I was couch-bound," Crovo said. "Small things like doing the dishes or simple housekeeping would knock me out for a day."

By late summer, however, Crovo was still experiencing symptoms — mostly tachycardia and extreme fatigue — that made it hard for her to do routine tasks. 

"If I was lying down, my heart rate was OK," she said. "Then I'd stand up and it was like my heart was running a marathon."

She applied for short-term disability. Her insurance company rejected her because, she said, her symptoms were too ambiguous and lacked a formal diagnosis.

The only alternative was to take unpaid leave from work, with her employer promising her job would be there for her. She was out for three months.

"That was the biggest hit for us," Crovo said. "We had to dip into savings, and I started using a credit card that I didn't use frequently."

Overall, the pursuit of a cure for her symptoms came with a significant cost, she said, as she consulted with a variety of specialists. At one point, she was going to physical therapy three times a week in an effort to help her heart not work so hard, she said.

Now, she's trying acupuncture, and each appointment has a $45 copay. However, a medicine she was using off-label to help treat her symptoms is no longer covered by her insurance and would cost $300 monthly if she were to resume taking it.

Crovo said she thinks the acupuncture is helping.

"I'm a lot better than I was last April, or August or December even," she said. "I'm able to get through the work day, which is good for me and our family."