Why COVID headaches can be hard to shake and when you should worry

For some people with COVID-19, the pain in their skull is so intense they consider a trip to the emergency room.

For others, it might come in throbbing waves or feel like a constant mild ache; it could be gone within minutes of taking painkillers or still be there months later.

"My head felt like it would explode, and no medication was enough to make it better," said Ananda Pires, who fell ill in late December.

After two days during which she was barely able to move from her bed, the Guelph, Ont., woman said her headache mostly disappeared, with just minor pain and sensitivity to light in the days that followed.

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While loss of smell, fever and dry cough may be more publicized symptoms of COVID-19, headache is a common one, too. And, two years into the pandemic, patients and physicians are beginning to recognize that, for some, it may be by far the worst symptom and one that lingers after others are gone.

It's why there's been a push by researchers, including the U.S. National Institutes of Health, to study the little-understood long-term neurological symptoms reported in some acute COVID-19 patients, which can include headaches, brain inflammation and damage to brain blood vessels.

While some people's headaches disappear alongside the illness, other patientscan't seem to shake them even long after their other COVID symptoms are gone.

Dr. Nili Kaplan-Myrth tested positive for COVID at the start of April. The Ottawa family physician is now well enough to resume seeing patients, but she still has an incessant headache that she describes as "like a vise."

"It's like you're wearing a hat that's too small," Kaplan-Myrth told CBC News. "It's a dull pain that's just always there."

For Scott Schmidt, the COVID headache "was like living under water for a few weeks,"with a constant pressure behind his eyes.

"I was like, I just cannot shake this headache for the life of me. I became used to it. I honestly just started going about my day with a headache," Schmidt, a journalist from Medicine Hat, Alta., said.

'Just a headache' or is it COVID?

Headaches are common to viral infections, including colds and flu. They are often one of the earliest symptoms of COVID-19, which, physicians have noticed, can make it difficult to distinguish whether it's just a headache or a sign of a developing illness.

Dr. Sumon Chakrabarti, an infectious disease specialist in Mississauga, Ont., says he's seen patients present at emergency rooms with a severe headache and then test positive for COVID.

But others might brush off a minor headache and not realize they're infected.

"So many people come and tell you, 'You know what? It was so weird, I had a little bit of headache, a little bit of a sore throat, I just thought I drank too much wine, but I was positive.'"

Chakrabarti said if someone develops a new headache in the middle of a rising wave of COVID, it's worth taking a rapid test.

He also points out that a sudden, severe headache can also be indicative of other medical emergencies, like a brain bleed, stroke or viral meningitis some symptoms of which can be similar to those of COVID.

"If you're having a massive headache and a high fever, it's also a good idea to go to the emergency [room]. If you're having a bad headache and vomiting that won't stop, you go in as well."

Headaches that just won't quit

For some people, the headache just won't go away long after they're no longer infected. Exactly why isn't yet well understood.

"There are multiple possibilities at this point, and I don't think we have a good handle on it yet," says Dr. Jennifer Frontera, a neurology professor at the NYU Grossman School of Medicine, who is researching post-COVID conditions.

Some of those possibilities, she says, include complications from severe COVID, autoimmune conditions, high blood pressure impacting blood vessels in the brain, or even pandemic stress that results in tension headaches.

Given the number of potential causes, she says, "it's worth going to a clinician and seeing what the treatment strategies are."

The good news is that most long COVID patients respond to existing treatments for headaches and migraines, says Dr. Angela Cheung, a long COVID researcher based out of Toronto's University Health Network.

Those treatments can include prescription medications, massage and mindfulness, depending on the diagnosis.

Cheung also reminds patients who despair about their long COVID symptoms that "it doesn't mean that you will have this forever."

Her advice: "Trying to deal with what you're currently experiencing one step at a time, because we are learning so much every day with COVID."

Headaches and another infection

Though Kaplan-Myrth is still struggling through her daily headache, the Ottawa physician also has another worry: if she gets reinfected in future, will the headache return?

"The fear that I could get COVID again and go through this again, particularly when I'm not back to baseline as it is, is just like, I don't think I would cope," she said.

It's a concern shared by Schmidt, whose COVID headache finally went away after about three weeks.

"Now I actually live in just a tiny little bit of fear Before, I was being careful because I pay attention and people told me to be careful," she said. "Now I'm being careful, because I'm actually legitimately concerned for myself."