By now you’ve likely heard of post-acute sequelae of SARS-CoV-2 (PASC), more commonly known as long COVID. it’s a collection of murky symptoms that persist or randomly show up more than four weeks after a COVID-19 infection, sometimes lasting for months, according to the Centers for Disease Control (CDC). And now, the CDC is saying 1 in 5 people who have been infected with COVID may be dealing with symptoms of long COVID.  The CDC recognizes an exhaustive list of long COVID symptoms including shortness of breath, fatigue, brain fog, cough, chest or stomach pain, headaches, and more. But if you ask doctors on the ground treating long COVID patients, there are quite a few sneaky symptoms that didn’t make the list.  Here are some additional symptoms to look out for, according to Dr. Tae Chung, MD, assistant professor of physical medicine, rehabilitation, and neurology, and director of the Postural Orthostatic Tachycardia Syndrome (POTS) Program at Johns Hopkins Medicine. Since even asymptomatic COVID patients can be plagued by long COVID, it’s worth self-monitoring for them whether your infection was mild or severe, and seeing a doctor if any of the symptoms below sound familiar.

8 sneaky symptoms of long COVID

Feeling woozy when you stand up

In a January 2021 article published in the medical journal Clinical Medicine, researchers found a connection between confirmed or suspected COVID-19 viral infections and orthostatic intolerance syndrome, which is marked by a drop in blood pressure and symptoms such fatigue, dizziness, heart palpitations, or difficulty breathing particularly when you move from sitting or lying to standing. While research is still underway, most experts chalk this up to autonomic nervous system failure or low blood volume, for which medical intervention can help.

Loss of appetite

It’s no secret that COVID-19 can affect your sense of smell and consequently, impact the way food tastes: Nearly 85 percent of patients report the symptom around the time of initial infection. However, 7.2 percent of patients continue to experience it 60 days later, according to The Journal of Laryngology & Otology study of 138 people who contracted coronavirus in 2019. Because it’s often the scent and taste of food that drives humans to eat, the symptom clinically referred to as olfactory dysfunction can seriously take a toll on appetite and nutrient intake—a big problem when you’re trying to recover from an illness.

Diarrhea, constipation, or both

Although COVID-19 was first identified as a respiratory infection, it’s now known that the virus can affect other organ systems, including the GI tract. As such, long COVID can be marked by unusual GI symptoms, according to a 2020 Journal of Microbiology, Immunology and Infection article. Among long COVID patients, Dr. Chung has fielded many reports of alternating diahhrea and constipation, which research suggests could be linked to compromised blood flow to the digestive system, changes in intestinal flora, or inflammation. 

Sweating

Whether it’s excessive sweating or a lack of sweating, any change that makes it difficult for you to adjust to new temperatures could be a sign of long COVID, Dr. Chung says. While research is still underway, abnormal sweating is reported by roughly half of long COVID patients and is suspected to be caused by nerve disfunction, according to a 2022 study published in Journal of Neurology. 

Shaking

Research suggests that tremors can be another sign of long COVID, particularly among patients who have been hospitalized for COVID, according to a study of 95 COVID-19 patients hospitalized during the onset of COVID-19 in spring 2020. Dr. Chung has fielded patient reports of excessive, uncontrollable, shaking: “Some people think they are having a seizure,” Dr. Chung says. “It’s not talked about often.” 

Blurry vision 

As many as one out of ten COVID-19 patients report at least one ocular symptom, according to a 2021 meta analysis of more than 6,300 COVID-19 patients. This could include blurry vision, but also dry eyes, a feeling that something is in your eye, itching, burning, pink eye, and more.  

Back pain

In a 2021 International Journal of Clinical Practice study of 280 COVID-19 patients conducted after acute infection, more than 70 percent reported spine pain and just over 30 percent reported more generalized pain in the back. While the vast majority of subjects (240) said COVID-19 simply aggravated preexisting issues, “it’s definitely a sneaky symptoms,” Dr. Chung says. 

Insomnia

If you wake up in the middle of the night feeling restless or open your eyes after 10 or 12 hours of sleep and fail to feel refreshed, long COVID could be the culprit, Dr. Chung says. Twenty-six percent of previously hospitalized COVID-19 patients reported sleep difficulties in a study conducted by Wuhan, China researchers in a 2021 Lancet study.

Why COVID causes symptoms long after infection

Long COVID is still being studied, but experts believe that organ damage, impaired blood circulation, and neurological issues can contribute to many of the symptoms listed above. Dr. Chung says some symptoms may result from the body’s involuntary fight or flight response, which increases circulating levels of adrenaline, epinephrine, and norepinephrine. As a result, you’ll experience symptoms that feel a lot like the body’s response to severe anxiety. An alternative theory is that inflammation caused by the COVID-19 virus and the body’s autoimmune inflammatory response can cause secondary problems throughout the body, Dr. Chung says. But doctors are still sussing out pathology, since COVID-19 is still so new, clinically speaking. 

What to do if you think you have long COVID

There’s no question that the best move is to give your primary care doctor a ring, since they can run symptom-specific tests and eliminate alternative causes to confirm or reject your suspicions. Regardless of the findings, a formal diagnosis will bring you one step closer to feeling better faster.  Next up: When to See a Doctor About Mild COVID Syptoms

Sources

Dr. Tae Chung, MD, Johns Hopkins MedicineOcular Manifestations of COVID-19: A Systematic Review and Meta-analysisThe syndromes of orthostatic Intolerance, European Society of Cardiology Autonomic dysfunction in ‘long COVID’: rationale, physiology and management strategies, Clinical MedicineThe Differential Role of Smell and Taste For Eating Behavior, PerceptionLong-COVID and Post-COVID Health Complications: An Up-to-Date Review on Clinical Conditions and Their Possible Molecular Mechanisms, Vaccines and Therapeutics against Coronaviruses6-month consequences of COVID-19 in patients discharged from hospital: a cohort study, LancetCOVID ‘Long Haulers’: Long-Term Effects of COVID-19, John Hopkins Medicine 8 Sneaky Signs of Long COVID - 45