Long COVID symptoms: A mysterious illness that may affect up to 80% of COVID cases
Long Covid is, quite possibly, the great enigma of our time.
Exactly what it is, when it appears, how long it lingers, how many patients it affects (from 10% to 80% of COVID survivors, depending on the study), and what just causes it—beyond the seemingly obvious—are debated, with new hypotheses floated daily.
As research into the vexing new disease expands, it seems that almost anything and everything could be a symptom—from ear numbness, a sensation of “brain on fire,” and erectile dysfunction to irregular menstrual periods, constipation, and peeling skin.
For those investigating the mysterious malady, that’s a real problem.
Recently scientists have attempted to categorize Long COVID patients into subgroups, hypothesizing that the condition that could affect up to 23 million Americans, according to federal officials, isn’t one thing, but many.
A picture is beginning to emerge of “groups of symptoms that have yet to be characterized well enough to call one or several diseases,” Justin Reese, a computational biologist with Berkeley Lab—a multi-science lab supported by the U.S. Department of Energy—told Fortune this week via email.
A study released last month used artificial intelligence to classify tens of thousands of U.S. “long haul” patients using their electronic health records. The main symptom sets his study found include patients who primarily suffer from:
Blood and circulatory system issues like heart failure, arrhythmias, and chest pain.
Respiratory system issues like throat and chest pain, upper respiratory infections, asthma, and lower respiratory disease.
Musculoskeletal and nervous system issues like connective tissue disorders, osteoarthritis, and musculoskeletal pain.
Digestive system issues like abdominal and pelvic pain, nausea, vomiting, and disorders of the urinary system.
But theories abound. Dr. Alexandra Brugler Yonts, an infectious disease specialist at Children’s National Hospital in Washington, D.C., recently shared her list of possible buckets with Fortune. They include patients who:
Have sustained long-term organ injury from COVID, such as lung damage.
Are suffering from inflammation resulting from COVID.
Have developed dysautonomia, which leads to changes in blood pressure and heart rate upon changes in position, like sitting or standing.
Have ongoing COVID viral activity.
Have immune systems that over-corrected in response to COVID and now under-respond to pathogens.
Categories may extend well beyond a handful, however, as symptoms have been identified in 10 of the 11 organ systems, according to a landmark study published in British medical journal The Lancet in July.
Here are 100 of the most common symptoms the study identified, by category:
Emotion and mood
Sense of doom
Pins and needles feeling
Ringing in the ears
Feeling of brain pressure
Sensation of brain "on fire"
Inability to yawn
Awakened by feeling of inability to breathe
Restless leg syndrome
Poor attention span
Short-term memory loss
Long-term memory loss
Forgetting how to do routine tasks
Inability to make new memories
Behind the eyes
Base of skull
After mental exhaustion
Taste and smell
Loss of taste
Loss of smell
Speech and language
Difficulty finding the right words
Difficulty understanding speech
Speaking unrecognizable words
Breathing difficulties but normal oxygen saturation
Cough with mucus
Coughing up blood
Rattling of breath
Shortness of breathe
Reproductive, genitourinary, endocrine
Bladder control issues
Burning in the chest
Loss of appetite
New anaphylaxis reactions
Head, ear, eye, nose, throat