CDC: Many COVID-19 patients who suffered mild illness being diagnosed with new ailments months later

A recent study from the U.S. Centers for Disease Control and Prevention found that among more than 3,000 non-hospitalized COVID-19 patients who suffered mild forms of the disease, two-thirds ended up being diagnosed with a new health condition up to five months after contracting the novel coronavirus. 

In a study published on April 23, the CDC looked at 3,171 adult COVID-19 patients who did not require hospitalization. They found that 69% had one or more outpatient hospital visits between 28-180 days after initially falling ill with the virus. 

The CDC noted that more than one-third of the patients required a new specialist visit. Specialist visits included gynecology, urology, orthopedic and general surgery. Specialists who deal with neurology, cardiology, and behavioral/mental health were also commonly seen by people who recovered from COVID-19. 

The CDC noted that a higher proportion of women and non-Hispanic Black adults had one or more outpatient visits than men and adults of any other racial or ethnic group. 

"This could be a result of certain groups being disproportionately affected by COVID-19, differences in care seeking and in the prevalence of underlying health conditions, or a higher risk for post–COVID-19 conditions among these populations," the CDC said. 

Study authors said that while frequency of outpatient visits for varying symptom diagnoses after a patient recovered from COVID-19 generally declined after 60 days, "they persisted beyond 120 days among some patients. Clinicians and health care systems should be aware of the possibility of medical encounters related to a previous diagnosis of COVID-19 beyond the acute illness."

Dr. Alfonso C. Hernandez-Romieu, the study’s lead author, told the New York Times that while many coronavirus patients suffered mild-to-moderate illness from COVID-19, "it’s possible you may experience new or persistent symptoms months after the initial diagnosis."

During the onset of the pandemic, many doctors were baffled by some of the deleterious effects caused by COVID-19 — originally thought to be just a respiratory illness. But mounting cases of COVID-19 patients who have suffered with a variety of symptoms months after testing positive for the virus illustrate that the residual effects of COVID-19 can be much more complicated. 

Radiological images published on Feb. 17 at Northwestern University detailed the various types of long-term effects of COVID-19, including rheumatoid arthritis flares, autoimmune myositis or "COVID toes," and more.

In the study published in the journal "Skeletal Radiology," the collections of images included ultrasounds, X-rays, MRIs, and CT scans which confirmed the causes of various COVID-19 symptoms.

"We’ve realized that the COVID virus can trigger the body to attack itself in different ways, which may lead to rheumatological issues that require lifelong management," said corresponding author Dr. Swati Deshmukh (

Currently, several symptoms of COVID-19 identified in the study are not recognized by the CDC. Symptoms like "COVID toes" and "rheumatoid arthritis" aren’t listed on the CDC’s website detailing long-term effects of the coronavirus.

According to the CDC, the most commonly reported long-term symptoms include:

  • Fatigue
  • Shortness of breath
  • Cough
  • Joint pain
  • Chest pain

Other reported long-term symptoms include:

  • Difficulty with thinking and concentration (sometimes referred to as "brain fog")
  • Depression
  • Muscle pain
  • Headache
  • Intermittent fever
  • Fast-beating or pounding heart (also known as heart palpitations)

More serious long-term complications appear to be less common but have been reported. They have been noted to affect different organ systems in the body. These include:

  • Cardiovascular: inflammation of the heart muscle
  • Respiratory: lung function abnormalities
  • Renal: acute kidney injury
  • Dermatologic: rash, hair loss
  • Neurological: smell and taste problems, sleep issues, difficulty with concentration, memory problems
  • Psychiatric: depression, anxiety, changes in mood

The CDC said, "While most persons with COVID-19 recover and return to normal health, some patients can have symptoms that can last for weeks or even months after recovery from acute illness."

According to a separate study from the National Institutes of Health (NIH), published in December, researchers found evidence to suggest that brain damage may be a byproduct of COVID-19. Researchers uncovered blood vessel damage and inflammation in the brains of 19 deceased COVID-19 patients.

RELATED: ‘Today is day 353’: Woman takes 189 pills a week nearly 1 year after COVID-19 diagnosis to combat symptoms

A more recent study from the NIH published on April 20 in the medical journal JAMA found that just over 1 in 10 health care workers who fell ill with mild forms of COVID-19 were still struggling with at least one moderate-to-severe symptom up to eight months later.

Amy Watson, a preschool teacher who lives in Portland, Oregon, is an example of a case of "long haul" COVID-19. 

She first tested positive for COVID-19 on April 11, 2020, after falling ill with flu-like symptoms in mid-March of last year. She experienced an array of frustrating symptoms a year after experiencing flu-like symptoms. 

"I pretty much wake up nauseous every morning," Watson said on March 3. 

Watson received an invitation by the NIH to participate in a neurological study on long-term COVID-19. Watson will travel to the NIH’s headquarters in Bethesda, Maryland with hopes of finding a light at the end of a long and arduous tunnel of illness. 

According to the NIH, the study will examine people with long-term symptoms in hopes of identifying the changes in the nervous system to better understand how the disease impacts the body.

The impact that COVID-19 has on the brain has been a concern of medical experts since the onset of the pandemic. 

A study published in November in the medical journal The Lancet Psychiatry suggested that COVID-19 survivors have a significantly higher rate of psychiatric disorders, dementia and insomnia.

Researchers captured data from the records of 54 health care organizations in the United States, totaling nearly 70 million patients, including 62,000 cases of the coronavirus.

"In patients with no previous psychiatric history, a diagnosis of COVID-19 was associated with increased incidence of a first psychiatric diagnosis in the following 14 to 90 days," the study authors wrote.

The study also suggested that individuals with a pre-existing mental illness were 65% more likely to be diagnosed with COVID-19 than those without.

RELATED: Study: COVID-19 diagnosis doubles risk of new mental illness

In addition, 1 in 5 survivors were recorded as having a first time diagnosis of anxiety, depression or insomnia.

This study echoes other research this year that has suggested that patients with COVID-19 have symptoms of anxiety — including post-traumatic stress disorder, depression and insomnia.

"I think this year in particular has really brought people face to face with so much that they may have not dealt with in the past," Dr. Isaiah Pickens, a licensed clinical psychologist and CEO of iOpening Enterprises (, said.

Data published in another study in August in the medical journal ScienceDirect, found that 22.5% of COVID-19 patients, among 40,469 diagnosed, had neuropsychiatric manifestations.

And even those who may not have been diagnosed with COVID-19 are still feeling its impacts psychologically. According to an August survey conducted by the CDC, 40% of Americans are struggling with mental health or substance abuse issues as the COVID-19 pandemic continues.

According to the CDC, during June 24-30, U.S. adults reported considerably elevated adverse mental health conditions associated with COVID-19, and symptoms of anxiety disorder and depressive disorder increased considerably in the United States during April–June of 2020, compared with the same period in 2019.

Stephanie Weaver, Kelly Hayes and FOX News contributed to this report.