In September 2021, I collapsed from exhaustion.

My vision went blurry. Then, my eyelids grew so heavy that I could barely keep them up for milliseconds at a time. Panicked, I stumbled approximately 50 yards toward a nearby friend, and slumped over her shoulders. She guided me to a shady spot under a tree, where I floated in and out of consciousness for about two hours.

As far as I knew, I was a healthy guy in my late 20s with no known risks of major health issues. I chalked it up as a one-off. But over the next few months, at unpredictable moments on random days, I'd hit a wall — going from perfectly fine to lying in the fetal position with a crushing headache, in the snap of a finger.

My friends and family eventually convinced me to see a doctor. A wide array of blood tests later, my diagnosis came back: a severe vitamin D deficiency and some high cholesterol. According to my doctor, both issues were pretty easy to connect to the sedentary lifestyle I'd lived since March 2020 — not going outside or exercising nearly as often as I did pre-Covid.

Curious if I was alone, I spoke with a half-dozen medical experts in fields ranging from internal medicine and oncology to dermatology and podiatry. All of them said that in recent months, they've seen upticks in health issues that don't involve contracting the Covid-19 virus, but are caused by the pandemic nonetheless.

And some people's experiences are a lot worse than mine.

A long list of health problems

Many forms of medical screenings ground to a halt when Covid hit, so some doctors today are diagnosing more advanced forms of cancer, diabetes and other chronic conditions than they did pre-Covid. The same delays in treatment, plus a wide variety of pandemic stressors, have also led to more diagnoses of mood, anxiety and substance-abuse disorders.

"We're seeing this across a broad age spectrum," Dr. Erica Johnson, chair of the American Board of Internal Medicine's infectious disease specialty board, tells CNBC Make It. "We're seeing adolescents and children impacted, and we're seeing lots of adults and older adults impacted, too. I think it's a real problem, and not likely to go away anytime soon."

Weight gain, stress and above-average levels of drinking are contributing to more heart disease. That same weight gain is also correlated with long-term or permanent mobility issues like collapsed foot arches and severe forms of Achilles tendonitis.

New exercise routines and pent-up energy in the pandemic's early months resulted in stress fractures and other overuse injuries. Going barefoot all day while working from home is leading to blisters, broken toes and structural problems with foot and ankle tendons. (I'm writing this, somewhat self-consciously, at home in socks.)

"I'm not necessarily seeing that many more patients — but what I'm seeing is a greater severity. It seems to be much more advanced by the time patients come to me," says Dr. Sean Peden, an assistant professor of orthopedic surgery at the Yale School of Medicine. "The severity and frequency are going up, which makes me think these are people who are probably hurting themselves more because of indirect causes of the pandemic."

Lots of mask-wearing can lead to face rashes, acne and dryness behind the ears. Frequent hand washing and sanitizing can lead to hand rashes or eczema. Even my vitamin D deficiency and high cholesterol are linked to increased odds of heart disease, stroke, diabetes, cancer, multiple sclerosis, weakened bones and immune system disorders.

That last one is particularly discomforting to hear during a global pandemic.

It's an extensive list, and likely an incomplete one. "If, in fact, Covid leads to an uptick in cancer mortality — and I think it probably will — it's not something we'll be able to detect statistically for another year or two," says Dr. Eric Winer, director of the Yale Cancer Center. "We may have much better research and far more accurate statistics about what really happens one, two, three years from now."

So, what can we do about it right now?

Learning to live with the pandemic's side effects

Even once Covid fades, some of the root causes will likely remain. Pandemic stress may outlive the pandemic itself. Remote work is here to stay, in one form or another. Mask-wearing could become seasonal, and doctors probably won't ever recommend washing your hands less.

Much like how we're learning how to live with Covid long-term, we'll need to learn how to live with the pandemic's non-virus effects, Johnson says. In some cases, that means resuming your pre-Covid health routines. Make annual eye doctor and dentist visits again. Return to annual mammograms and routine vaccinations. Consider mental health screenings on a semi-regular basis.

In other cases, you may need to create new habits. Peden, for example, recommends five to 10 minutes of hamstring and calf stretches per day, and indoor footwear for anyone working from home. "You want it to be comfortable, but comfort is secondary to protection," he says. "If it bends like a sock or it's floppy like one of these slippers that looks like a stuffed animal, that's not really protecting your feet."

Similarly, if your skin is struggling after two years of Covid precautions, the solution isn't to stop wearing masks or washing your hands, emphasizes Dr. Sarika Ramachandran, an associate professor of dermatology at the Yale School of Medicine. Rather, she says, those struggles mean you're probably at risk of deeper skin dryness issues regardless — and moisturizing your face and hands more often will likely solve both problems.

And if you're anything like me, swallow your pride and ask your doctor about your own personal situation — even if you don't think anything is wrong. My fatigue was a slow burn: Until I spoke with my doctor, I didn't fully realize just how much my day-to-day stamina had tanked.

When he prescribed me 50,000 international units (IUs) of vitamin D3 per week — a huge amount, relatively speaking — he looked at me with eyebrows raised above his mask. "You'll be back to your normal, bouncy self in no time," he said, wryly.

I laughed, because I didn't generally feel listless or low-energy. But the morning after I took that first comically overdosed pill, I immediately felt the difference. It was, without exaggeration, like night and day.

I felt like myself again.

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