Too much cortisol and too little cortisol can both leave you exhausted, foggy, and unwell — which is exactly why people confuse them. Cortisol is your body’s key stress hormone, and health depends on having the right amount at the right time. This guide breaks down high vs low cortisol: the symptoms of each, what causes them, how they overlap, and when you should get tested.
If you’re new to the topic, start with what is cortisol.
The quick comparison
| High cortisol | Low cortisol | |
|---|---|---|
| Common feel | “Wired but tired,” anxious | Exhausted, flat, depleted |
| Weight | Gain, especially belly & face | Unexplained weight loss |
| Blood pressure | Often high | Often low; dizziness on standing |
| Appetite / cravings | Sugar & salt cravings, more appetite | Poor appetite; strong salt craving |
| Sleep | Trouble falling asleep, 3 AM waking | Unrefreshing sleep, hard to get going |
| Skin | Acne, thinning, easy bruising | Darkening of skin (in Addison’s) |
| Mood | Anxiety, irritability | Low mood, apathy |
Signs of high cortisol
Chronically elevated cortisol usually comes from ongoing stress and lifestyle, and sometimes from a medical condition. Common signs include:
- Weight gain around the belly and face
- Feeling “tired but wired,” especially at night
- Trouble sleeping and waking around 3 AM
- Sugar and salt cravings
- Anxiety, irritability, and brain fog
- High blood pressure and frequent illness
We cover these in depth in 15 signs of high cortisol. Severe, persistent high cortisol from a medical cause is called Cushing’s syndrome and has more dramatic signs — a rounded “moon” face, purple stretch marks, and rapid weight gain — that require medical diagnosis.
Signs of low cortisol
Low cortisol is less common but important. Genuine, medically low cortisol — as in Addison’s disease or adrenal insufficiency — can cause:
- Extreme, persistent fatigue that rest doesn’t fix
- Unexplained weight loss and poor appetite
- Low blood pressure, dizziness, or fainting when standing
- Strong cravings for salt
- Nausea, and sometimes darkening of the skin
- Muscle weakness and low mood
Important: true adrenal insufficiency is a serious medical condition that needs diagnosis and treatment — it is not the same as the popular term “adrenal fatigue,” which isn’t a recognized medical diagnosis.
Why the symptoms overlap
Here’s the tricky part: fatigue, brain fog, low mood, and poor sleep show up in both high and low cortisol. That’s because cortisol works best within a healthy range and a healthy daily rhythm — stray too far in either direction and the body struggles. It’s also why you can’t reliably tell high from low based on how you feel alone. The timing matters too: cortisol that’s normal in the morning would be “high” at midnight.
What causes each?
| High cortisol causes | Low cortisol causes |
|---|---|
| Chronic psychological stress | Adrenal insufficiency (Addison’s disease) |
| Poor sleep, shift work | Pituitary problems reducing ACTH |
| Over-training | Long-term steroid use then abrupt stopping |
| Some medications (corticosteroids) | Certain autoimmune conditions |
| Cushing’s syndrome (tumor-related) | Damage to the adrenal or pituitary glands |
How is cortisol tested?
Because symptoms overlap and timing matters, testing is the only way to know for sure. Options include:
- Blood test — a morning cortisol level, often the first step.
- Saliva test — often done late at night or across the day to map your rhythm.
- 24-hour urine test — measures total cortisol output over a day.
- Stimulation/suppression tests — ordered by a doctor to pinpoint high or low cortisol causes.
A single reading rarely tells the whole story; mapping the daily curve is more revealing — see the cortisol curve.
What to do next
If your cortisol is high from lifestyle stress (the most common situation), the fix is sleep, nutrition, movement, and stress management — start with how to lower cortisol naturally.
If you suspect low cortisol — persistent extreme fatigue, weight loss, low blood pressure, salt cravings, dizziness — this needs medical evaluation, not lifestyle tweaks. See a doctor promptly.
When to see a doctor
Get medical advice if you have severe or persistent symptoms, especially rapid weight change, fainting, very high or very low blood pressure, or extreme fatigue. Cortisol disorders are treatable, but they require proper testing and care — self-diagnosis from a symptom list isn’t enough.
Frequently asked questions
How do I know if my cortisol is high or low?
You often can’t tell from symptoms alone, because fatigue and brain fog occur with both. High cortisol tends to bring weight gain, anxiety, and “tired but wired” nights; low cortisol tends to bring weight loss, low blood pressure, and salt cravings. Testing (blood, saliva, or urine) is the only reliable way to know.
Can you have high and low cortisol at different times?
Yes. Cortisol naturally rises and falls across the day. A disrupted rhythm can leave it too high at night and too low in the morning, which is why mapping the full curve is more useful than a single reading.
Is “adrenal fatigue” the same as low cortisol?
No. “Adrenal fatigue” is a popular term, not a recognized medical diagnosis. True low cortisol (adrenal insufficiency or Addison’s disease) is a distinct, serious condition diagnosed with lab tests.
Which is more common, high or low cortisol?
Chronically high cortisol from lifestyle stress is far more common. Genuinely low cortisol from adrenal insufficiency is relatively rare but medically important.
Medical disclaimer: This article is for educational purposes only and is not medical advice. It has not been evaluated by the FDA and is not intended to diagnose, treat, cure, or prevent any disease. If you suspect a cortisol disorder, consult a qualified healthcare provider for proper testing.
