You’re tired, achy, stressed, and you can’t seem to get a good night’s rest. So what gives? A quick search on Dr. Google provides a seemingly common diagnosis: adrenal fatigue.

But here’s where we remind you that the Internet is not a doctor. Because guess what? Adrenal fatigue might not even be a real thing. Yup.

The term adrenal fatigue was coined by James Wilson, Ph.D., a naturopathic doctor, in his 1998 book Adrenal Fatigue: The 21st Century Stress Syndrome and is said to classify symptoms related to under-performing adrenal glands.

Quick anatomy lesson: The adrenal glands are very tiny glands located just above the kidneys. You have two adrenal glands, a right and a left.

Each gland has two specialized layers: an outer layer (the cortex) and an inner layer (the medulla). For tiny glands, they pack quite the punch. “The glands make several hormones that are released directly into the blood stream and are essential for life,” says Christopher Palmeiro, D.O., the chairman of endocrinology at HealthAlliance of the Hudson Valley and the founder of Doctablet, an online resource that helps people better understand medical conditions.

The cortex makes three classes of hormones—mineralocorticoids (like aldosterone, which helps regulate blood pressure as well as sodium and potassium levels), glucocorticoids (like cortisol, the stress hormone), and androgens (or sex hormones).

Related: 8 Possible Reasons Why You’re So Tired All The Time

Cortisol is a really important one, Palmeiro notes, as it helps your body respond to stress, fight infections, and regulate your blood sugar levels and body temperature.

And the medulla? It’s responsible for making adrenaline. “This specialized inner layer of the adrenal gland is considered to be a part of the body’s nervous system, helping the body respond to stress,” says Palmeiro.

So yeah, you want your adrenal glands to perform well. The thing is, while it can be frustrating to experience symptoms like sleep problems, cravings, tiredness and fatigue, digestive issues, and body or muscle aches, adrenal fatigue isn’t considered to be a ‘real’ diagnosis, according to Palmeiro

“The idea that long-term emotional or physical stress overburdens the adrenal gland—causing an adrenal gland burn-out—has not been substantiated,” says Palmeiro. “There has been no convincing research on the topic.”

Not to mention, such nonspecific symptoms can point to other health conditions and lifestyle issues, such as depression or anxiety, inflammatory bowel disease (IBD), a poor diet or a lack of exercise, and more.

Palmeiro also points out that there is an important difference between adrenal fatigue and adrenal insufficiency. The latter is a rare medical condition that crops up when your adrenal glands don’t produce enough hormones, he says.

Only about 1 in 100,000 people in the U.S. suffer from it, according to the National Organization for Rare Diseases, and it usually stems from damage to the glands themselves or a problem with the brain’s pituitary gland, which tells the adrenals to create cortisol.

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Adrenal insufficiency (also called Addison’s disease) can be confirmed through a blood test—and it’s worth treating. “Patients with low levels of cortisol may experience darkening of the skin, tiredness, weight loss, nausea, vomiting, low blood pressure, muscle pains, and salt cravings,” says Palmeiro. “In extreme circumstances adrenal crises can occur and lead to collapse and death.”

The condition is treated with medications that supply doses of the hormones you may need.

And speaking of medication, that’s actually the most common cause of true adrenal dysfunction, says Palmiero. Steroids like prednisone—used for inflammatory conditions—can suppress your body’s own ability to make cortisol if they’re used too much over time. If you need to be prescribed steroids, make sure they’re prescribed sparingly and tapered appropriately, advises Palmiero.

The bottom line? If you’re suffering from symptoms like fatigue, GI distress, and trouble sleeping, it’s best to touch base with your IRL doctor to ID the root of the problem. Google can only do so much.