Low cortisol symptoms: what to watch for and what else causes them

Low cortisol symptoms build slowly and look like many other problems. NIDDK lists the most common ones as long-lasting fatigue, muscle weakness, loss of appetite, weight loss and belly pain. Most people have felt tired, weak or off their food at some point, so the list alone can’t tell you much. This page covers which symptoms point more strongly toward the adrenal glands, what else produces the same symptoms, and when to see a clinician.

Some symptoms are an emergency. If you have an adrenal condition or take a steroid medicine, vomiting you can’t stop, severe diarrhea, fainting or weakness so severe you can’t do your usual activities needs 911 or the emergency room, not a test. See adrenal crisis.

Cortisol AM and PM

A morning result and a later one, because cortisol changes through the day. Follow the times on your lab order.

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Not for emergencies. If you have repeated vomiting, severe weakness or fainting, get urgent care instead of ordering a test. If you take a steroid medicine, ask your prescriber how it affects results.

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The symptoms of low cortisol

“Low cortisol” in this context means adrenal insufficiency, where the body doesn’t make enough cortisol. NIDDK lists these.

Most common

• Long-lasting fatigue
• Muscle weakness
• Loss of appetite
• Weight loss
• Abdominal pain

Also listed

• Nausea, vomiting or diarrhea
• Low blood pressure that drops further when you stand, causing dizziness or fainting
• Irritability and depression
• Joint pain
• Craving salty food
• Low blood sugar
• Irregular or absent periods
• Loss of interest in sex

Skin darkening. In Addison’s disease the skin can darken. NIDDK says this shows most on scars, skin folds, pressure points such as the elbows, knees, knuckles and toes, the lips, and the lining of the cheek.

How often these show up depends on who you ask. In one small study of 60 people at a single clinic in Poland, all had loss of appetite and weight loss, and 57 had darkened skin (the other three had generalized vitiligo) (Int J Endocrinol, 2013). Those patients already had primary adrenal insufficiency. The study shows what the disease looked like in people who had it. It doesn’t tell you how likely a given symptom is to mean the disease in someone who doesn’t know.

Why it is hard to spot

NIDDK says symptoms come on slowly, so they may be overlooked or confused with other illnesses, and that sometimes they first appear during an adrenal crisis.

The Polish authors describe the same trap. They say the symptoms of adrenal insufficiency resemble stomach and bowel disease (belly pain, poor appetite, nausea, vomiting, weight loss), muscle disease, or depression. Their most common wrong diagnosis was stomach or duodenal ulcer disease. Five patients had been admitted to other hospital wards with the same symptoms in the year before diagnosis and sent home without a diagnosis. Of the 60 people, 26 were first diagnosed during an adrenal crisis (13) or just as the signs of one appeared (13).

That is the case for getting persistent symptoms looked at. It is not a reason to assume your own tiredness is adrenal.

What else causes the same symptoms

MedlinePlus says fatigue is a symptom, not a disease. Its list of causes includes:

• Diabetes, COPD, and heart, liver, kidney and thyroid disease
• Anemia
• Infections
• Sleep apnea and other sleep disorders
• Depression and anxiety
• Some medicines, such as antidepressants and antihistamines
• Lifestyle habits such as too little sleep, too much alcohol or caffeine, and too little or too much exercise

Conditions can also sit side by side. A review of autoimmune primary adrenal insufficiency says it occurs together with other autoimmune disorders in more than 60% of cases, and that a slightly raised TSH can appear in primary adrenal insufficiency. The Polish authors note that weakness in their patients could also come from hypothyroidism, anemia or low B12 alongside the adrenal problem. So a finding of thyroid disease or anemia doesn’t rule the adrenal glands out, and an adrenal cause doesn’t explain every symptom.

If tiredness is your main symptom, anemia and thyroid disease are the two causes above that a simple blood test can look for. Ferritin shows iron stores, and TSH is a common first thyroid check. A clinician decides whether you need either. Our page on thyroid or adrenal tests for tiredness covers the order of checks.

• TSHA common first check of the thyroid $39 See this test at HealthLabs
• FerritinYour body's iron stores $29 See this test at HealthLabs

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Symptoms that point more toward the adrenal glands

None of these proves anything. A clinician weighs them with your history and lab results.

• Darkened skin or patches in the creases of the palms and inside the cheek. The 2023 review calls skin darkening notably specific to primary adrenal insufficiency.
• Dizziness or fainting when you stand. Low blood pressure that drops further on standing is on the NIDDK list.
• Craving salty food. Also on the NIDDK list. The review ties it to low aldosterone, a second adrenal hormone. Only a few of the 60 Polish patients reported it.
• Low blood sugar. Also on the NIDDK list.
• Routine blood work that shows low sodium, high potassium or low glucose. The review says these findings increase suspicion. In the Polish study, low sodium had been present for at least three months before diagnosis in 34 of 60 patients without leading to a diagnosis. See sodium and potassium in adrenal work-ups.
• A history that fits. NIDDK says the most common cause overall is suddenly stopping steroids taken for a long time. Pituitary surgery and traumatic brain injury are other causes it lists. See causes of low cortisol.

Primary and secondary can look different

Primary adrenal insufficiency (Addison’s disease) is damage to the adrenal glands. Secondary means the pituitary isn’t sending enough ACTH. NIDDK notes that people with secondary adrenal insufficiency usually make enough aldosterone. The review links low aldosterone to low sodium, high potassium and salt craving. Put together, that suggests those features are less expected in secondary cases, though neither source says so directly. NIDDK also says darkening is described in Addison’s disease, and the review calls it specific to the primary form. Because the pituitary makes many hormones, NIDDK adds that ACTH may not be the only one that is short.

In women and in men

The core symptoms are the same. NIDDK lists irregular or absent periods and loss of interest in sex. The 2023 review says low energy and low sexual responsiveness in women, and erectile dysfunction in men, are associated with a shortage of adrenal androgens, a third group of adrenal hormones. See low cortisol in women and men for the rest.

Does low cortisol cause anxiety, insomnia or headaches?

NIDDK lists irritability and depression among the symptoms of adrenal insufficiency. Neither NIDDK nor MedlinePlus lists anxiety, trouble sleeping or headaches. Each has many other common causes, so none is a useful sign of low cortisol by itself. If anxiety or sleep is the problem, see cortisol and anxiety and cortisol and sleep.

High cortisol and low cortisol symptoms side by side

MedlinePlus gives these lists for the two conditions.

Too much cortisol (Cushing syndrome)	Too little cortisol (adrenal insufficiency)
Weight gain	Long-lasting fatigue
Thin arms and legs	Muscle weakness
Round face	Loss of appetite
Fat at the base of the neck or between the shoulder blades	Weight loss
Easy bruising	Abdominal pain
Wide purple streaks on the stomach, breasts, hips and under the arms
Muscle weakness

Muscle weakness appears in both columns. Weight goes up with too much cortisol and down with too little. See high cortisol for the other side.

Low morning cortisol and symptoms

A low morning cortisol is a lab result, not a symptom. Doctors look at the morning value because cortisol is highest then, but no symptom lines up with a particular number. The result is read with your symptoms, ACTH and often a stimulation test. See low cortisol for how the steps fit together.

What about “adrenal fatigue”?

Online symptom lists for adrenal fatigue include tiredness, sleep problems, trouble coping, body aches, digestive problems and reliance on caffeine. A 2024 paper in the Journal of the Endocrine Society says adrenal fatigue has never been scientifically proven to exist, and that its symptom scores have never been validated. If that list sounds like you, the next step is still a clinician who can look for real causes. See adrenal fatigue.

When to see a clinician

MedlinePlus advises contacting your provider if you have been tired for weeks. NIDDK says that if you always feel tired, weak or are losing weight, you should ask whether you might have adrenal insufficiency, and that early treatment can help avoid a crisis.

Before the visit, write down:

• When each symptom began and how it has changed.
• Every medicine you use, including steroid pills, inhalers, creams and injections. Suddenly stopping long-term steroids is the most common cause of adrenal insufficiency, so this matters.
• Any pituitary surgery, head injury or autoimmune diagnosis.

NIDDK’s diagnosis page says doctors review your symptoms and history, then use blood tests, and that the ACTH stimulation test is the one used most often. A single cortisol result can’t diagnose adrenal insufficiency or rule it out.

If you are thinking about ordering a test

A morning cortisol with a later sample can give you a number to take to a clinician, if you have no emergency signs. It is a first look and not a work-up. An unusual result still leads to ACTH or a stimulation test arranged by a clinician. The seller’s page for its AM and PM test is unclear about when the second sample is taken and doesn’t say whether it is one visit or two. Check this before you order and follow the timing on your lab order. Our page on AM and PM timing covers the practical side. If you take a steroid medicine, tell your prescriber before testing, and don’t stop or change the medicine for a test.