Have you felt a little worried or stressed out over anything lately? Most people would say yes, citing reasons ranging from the demands of work to personal relationship problems.

On one hand, worrying every now and then is a completely normal aspect of life for everyone. As a matter of fact, it serves a purpose in the right kind of situation. In a situation where the outcome is controllable, stress may push you to work harder and come up with a strategy. Or if you happen to be in danger, stress leads your body into fight-or-flight mode and provides an adrenaline boost. 

"Experiencing a manageable amount of anxiety and worry helps prepare us to face the challenges of daily living," explains Dr. Adam Borland, a psychologist at the Chagrin Falls Family Health Center, Ohio.

But when you worry unnecessarily or excessively, your stress could make you sick in the literal sense. So how does this happen?

As mentioned earlier, high levels of stress increase cortisol levels and trigger the fight-or-flight response in the body. This helped our ancestors prepare to attack or defend themselves from common dangers such as wild animals. Comparatively, our survival is not under regular threat in the modern age.

The excess cortisol also triggers nausea, rapid heart rate, shortness of breath, headache, and other physical reactions. This may explain why you feel physically sick when particularly worried or anxious over something.

Normally, these responses disappear when your cortisol levels return to normal. But if you are constantly stressed out, the levels stay elevated — which is not good news for your well-being. In the long run, chronic stress can contribute to heart disease, diabetes, respiratory disorders, and gastrointestinal problems.

Even in the short term, you may be more prone to mild illnesses since anxiety can weaken your immune system and its germ-fighting capabilities. So it may not be a coincidence that you developed an infection before that big presentation or that crucial job interview.

"When people are stressed, they get sick. It could be a cold or cold sores, which pop up because the immune system can’t suppress the virus," states Shanna Levine, M.D., from the Icahn School of Medicine at Mount Sinai in New York City.

While you cannot avoid worrying 100 percent of the time, you can learn to manage your stress levels. The next time you feel overwhelmed about something, slow down and ask yourself — is stressing out about this helpful in any way?

Experts emphasize compassion and self-care more than anything. This especially applies to people who are too critical of their mistakes, those who try to carry the emotional burden of others, and the workaholics who refuse to take much-needed breaks. And if need be, reach out to professional mental health services and support groups.