The endocrine system is made up of glands located throughout the body. These glands produce hormones that are released into the bloodstream to regulate biological processes.

Researchers have discovered many ways Covid interferes with this critical system of chemical “messengers” in the body, affecting everything from blood sugar control (insulin), energy production (thyroid function), and reproductive function (testosterone, estrogen). Covid has been linked to increased risk of adults and children alike being diagnosed with diabetes for the first time. Already having diabetes significantly increases the risk of serious complications when infected with Covid.

The search for a “biomarker” for Long Covid — an important tool in diagnosis and justifying treatment — has led researchers toward the stress hormone cortisol, which controls how the body makes and uses energy (among other roles in body regulation). Those suffering from Long Covid show uniformly low levels of cortisol: a finding that may help direct scientists toward the development of effective treatments.