Waking up exhausted day after day is just one signal that you're not feeling well. But how do you know if you're just plain tired or have adrenal fatigue syndrome? The syndrome is a serious endocrine or hormonal disorder that occurs when the adrenal glands, located at the top of each kidney, produce too little or too much of certain hormones such as cortisol.

Adrenal fatigue has been thrown around as a "minor form of adrenal insufficiency" and a catch-all for many unexplained symptoms. It’s also a disorder that isn’t recognized by the American Medical Association, something that worries Debi Silber, R.D., a functional diagnostic nutritionist, who has experienced it twice.

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"I went through exhaustive testing with no answers or help and it was only when I did my own research that I learned how adrenal fatigue is one of the most common, yet undiagnosed conditions facing so many people today," Silber says.

In fact, Silber believes that the syndrome only gets recognized when it reaches the extremes of the disorder — appearing as either Addison's disease, a rare condition in which the adrenal glands gradually stop functioning, or Cushing's disease, which results from excess levels of the hormone cortisol in the body.

The adrenal glands are a key regulator that produce hormones that help us control blood sugar, burn protein and fat, react to stressors and regulate blood pressure.

What makes a diagnosis difficult is that individuals may experience symptoms such as weight gain, exhaustion, anxiety, hormonal issues, sleeplessness, low libido, digestive issues, muscle tension and thyroid issues, and those symptoms may overlap with other possible disorders and prevent individuals from getting the help they need, Silber says.

"All of the symptoms that have us feeling horrible are ones that can be due to so many other health problems," she says. "A diagnosis is so hard to pin down."

However, there are some experts who are quite vocal about giving adrenal fatigue syndrome the credence it deserves.

"This syndrome comes about due to the lack of the necessary output of cortisol that can reduce inflammation in the body," says Barry Sears, Ph.D., a research scientist and author of "The Zone." "Like Type 1 diabetes, adrenal fatigue is most likely due to a similar inflammatory destruction of the cortisol-secreting cells in the adrenal glands."

In addition, this means that adrenal fatigue syndrome shares some similar attributes to such serious autoimmune diseases as rheumatoid arthritis.

The reasons we may be seeing more cases of this syndrome today may be directly related to the way we eat, including our consumption of processed foods, Sears believes. A diet that's high in processed foods may, in turn, be contributing to our elevated levels of diet-induced inflammation.

So what can be done about this? Follow Sears' lead and aim to follow a strict anti-inflammatory diet, which includes eating oily, wild-caught cold water fish at least two times a week or supplementing with high-dose fish oil to reduce inflammatory response. It also means doing your best to eat "clean."

"By doing this, you'll reduce not only the need for higher levels of cortisol to reduce existing inflammation, but also reduce the likelihood of further inflammatory damage to the hormone-secreting cells in the adrenal gland," he says.