COVID-19 has touched all corners of the world -- and fear, anxiety, and grief have followed in its wake. The pandemic has taken a toll on the mental health and well-being of many, due to the climbing death toll, the social isolation, the constant internal monologue for some asking "do I have the virus?" and more, experts say.
Mental and physical health are intertwined and sometimes stress can manifest itself physically, according to experts. So if you're having migraines, have missed a period, lost hair, or had other irregularities in your daily life, it may be due to pandemic stress, they said.
"Think about it like erosion," said Craig Sawchuk, a psychologist at the Mayo Clinic, in an interview. "It just leads to wear and tear across time."
However, there may be other underlying causes for these issues. Ailments that someone experiences during a stressful time should not solely be attributed to stress, and the Mayo Clinic recommends that symptoms be evaluated by a medical professional.
According to psychology experts, when people are under mental stress, there is a fight or flight response from the central nervous system.
Sawchuk said the body uses a high amount of energy to deal with whatever the threat may be, which is why people can experience a rush of adrenaline, an elevated heart rate, increased blood pressure, heavier breathing and tense muscles.
Because of the amount of energy needed to tackle what's causing stress, vital organs, muscles, and systems steal resources from other non-essential systems in the body, said Kory Floyd, a professor of communication and psychology at the University of Arizona.
MORE: 'Striking' impact of COVID-19 pandemic on adolescent mental health"The mind is saying to itself, 'those systems are important, but they're not important if our survival is at stake.'" Floyd told ABC News. "When you pull resources away from those systems, they don't function optimally, which is why we end up with stomach aches or why we end up having a hard time getting pregnant, why we end up with a headache or having a difficult time sleeping."
When that acute stress lasts for long periods of time -- like a pandemic that is almost two years old -- it can cause trouble for the less essential systems of the body and disrupt their functions.
"It's almost like that sympathetic nervous system volume knob has just been cranked this entire time," Sawchuk told ABC News. "It's causing other systems to shut down, like digestion and reproduction. This is where you get things like missed periods, low sex drive … hair loss and skin-related problems because we're not getting into a restoration mode."
Stress begins to deeply affect people physically. It may look different on every individual, experts say, but some symptoms are more common than others.
"The body can only produce so many symptoms," Sawchuk said. "When we look at each individual, they may tend to express their distress or experience that stress in different ways. So for some people, it may show up in their skin," such as acne or psoriasis.
Sawchuk added, "For other people, it may show up in terms of just being exhausted."
The clinical psychologists interviewed by ABC News say they've seen an increase in reports of headaches, migraines and sleep disruptions among patients during the pandemic.
MORE: How Simone Biles shined a golden light on mental health this year: The Year 2021Chronic stress can also cause digestive issues and stomach-related problems. Low sex drive and missed menstruation cycles -- that are not caused by pregnancy -- may also be signs that stress is starting to disrupt one's reproductive systems.
One study in the Journal of Dermatological Treatment found that short-term stress-related cases of alopecia areata, an autoimmune disorder that causes hair loss, increased following the start of the pandemic, and researchers expected the number to continue to rise. Other psychiatry-related dermatologic diseases were also expected to rise, including psoriasis and chronic hives.
Aches and pains in the body, especially tension in the jaw and neck may also be due to stress.
Cindy Ackrill, an editor at the American Institute of Stress, says there is no shame in taking steps to alleviate stress and better one's mental health. These issues won't be reversed in the blink of an eye, Ackrill says, and there are simple ways to start the process towards healing.
"The first thing is to notice what tends to rev you up and what tends to calm you down," Ackrill said. "You can start to balance those out again -- what depletes your energy, what re-energizes you -- so that you can strategize to put those back together in the immediate feeling of stress."
MORE: Anxiety, depression fluctuated with COVID-19 waves: StudyExperts say leaving stress-related issues unchecked can lead to serious, long-term health problems. If you may be exhibiting symptoms of chronic or intense stress, seek help.
"Look for tiny little differences you can make," Ackrill advised. "Going to bed five minutes earlier, spending five minutes on the phone with a friend. Look for tiny little shifts you can make that don't feel like a lot of work."
Ackrill added, "We live in a world that's very stressful and we are all on a journey together to figure out how to do it."