An adrenal crisis is a life-threatening emergency that happens when your body’s cortisol levels drop dangerously low, causing blood pressure to plummet and organs to start failing. It’s defined clinically as a sudden health deterioration with systolic blood pressure falling below 100 mm Hg, or dropping at least 20 mm Hg below your usual baseline. Without rapid treatment, it can progress from vague flu-like symptoms to shock, coma, and death within hours.
Why Cortisol Matters This Much
Cortisol is a hormone produced by your adrenal glands, two small organs that sit on top of your kidneys. It does far more than manage stress. Cortisol keeps your blood vessels toned and responsive, maintains blood sugar between meals, regulates how your body handles salt and water, and controls inflammation. When cortisol suddenly drops to near zero, your blood vessels lose their ability to constrict, blood pressure collapses, blood sugar crashes, and your body can’t mount a normal response to even minor physical stress.
This is why something as ordinary as a stomach bug can become deadly for someone with adrenal insufficiency. Their adrenal glands can’t ramp up cortisol production the way a healthy body would during illness, so the gap between what the body needs and what it can produce widens until systems start shutting down.
Who Is at Risk
Adrenal crisis almost always occurs in people who already have some form of adrenal insufficiency, whether they know it or not. There are two main types, and the distinction matters because they look slightly different in a crisis.
Primary adrenal insufficiency (Addison’s disease) means the adrenal glands themselves are damaged. Because these glands also produce a hormone called aldosterone that controls salt and water balance, people with Addison’s lose both cortisol and aldosterone. This makes them prone to severe dehydration, dangerously high potassium levels, low sodium, salt cravings, and significant drops in blood pressure when standing. Their skin may also darken in unusual places.
Secondary adrenal insufficiency happens when the pituitary gland in the brain stops sending the signal that tells the adrenals to make cortisol. This is actually more common than Addison’s, and the most frequent cause is long-term use of steroid medications like prednisone. When you take steroids for weeks or months and then stop abruptly, your pituitary may not restart its signaling fast enough, leaving you cortisol-deficient. People with secondary insufficiency typically still produce aldosterone, so they’re less likely to have severe dehydration or high potassium. They are, however, more prone to dangerously low blood sugar.
Prospective studies estimate that people with primary adrenal insufficiency experience roughly eight adrenal crises per 100 patient-years. The mortality rate sits at about 0.5 deaths per 100 patient-years, a number that’s striking because these deaths are largely preventable with proper preparation.
Common Triggers
The single most common trigger is a gastrointestinal or flu-like illness. Vomiting and diarrhea are particularly dangerous because they prevent the body from absorbing oral steroid replacement medication, creating a rapid cortisol deficit at exactly the moment the body needs more of it. Other triggers include:
- Infections of any kind, especially those causing fever
- Surgery or medical procedures, even minor ones like dental work
- Physical trauma such as fractures or car accidents
- Emotional stress that’s severe or prolonged
- Suddenly stopping steroid medication without tapering
- Dehydration from heat, exercise, or not drinking enough fluids
In some cases, adrenal crisis is the first sign that someone has adrenal insufficiency at all. They may have had mild, undiagnosed symptoms for months until an illness or injury tips them into full crisis.
Symptoms and How They Progress
What makes adrenal crisis tricky is that it often starts looking like a dozen other things. Early symptoms are vague: fatigue, weakness, nausea, loss of appetite, mild dizziness. Many people initially assume they just have the flu.
As the crisis deepens, the symptoms become more alarming. Vomiting and severe abdominal pain can mimic a surgical emergency. Some people develop pain in their lower back or flanks. Blood pressure drops, heart rate climbs as the body tries to compensate, and breathing becomes rapid. Fever is common even without an obvious infection. Excessive sweating, particularly on the face and palms, can occur.
In advanced stages, confusion sets in, followed by extreme drowsiness, loss of consciousness, and eventually coma. The entire progression from “feeling off” to life-threatening shock can happen over the course of a single day, sometimes faster if the trigger is severe.
How It’s Diagnosed
In an emergency setting, doctors don’t wait for lab results to treat a suspected adrenal crisis. Treatment starts immediately based on symptoms, medical history, and low blood pressure readings. Blood is typically drawn before treatment begins so levels can be checked afterward.
For confirming adrenal insufficiency as the underlying cause, doctors use a stimulation test that measures how your adrenal glands respond to a synthetic version of the hormone that normally triggers cortisol production. Historically, a normal response was considered a cortisol level of 18 micrograms per deciliter or higher at 30 or 60 minutes after the injection. Newer, more precise lab methods have suggested that a cutoff of 14 to 15 micrograms per deciliter may be more accurate with current testing technology. A baseline cortisol level below 2 micrograms per deciliter strongly suggests the adrenals are not functioning.
Common lab findings during a crisis include low sodium, high potassium (mainly in primary insufficiency), low blood sugar, and signs of dehydration.
Emergency Treatment
Adrenal crisis requires immediate treatment with a large dose of replacement cortisol, typically 100 mg of hydrocortisone given by injection. This is followed by continued hydrocortisone over the next 24 hours, either as a continuous drip or as injections every six hours. At the same time, aggressive fluid replacement begins with saline solution, often starting with a rapid 500 ml bolus over 15 minutes and then 3 to 4 liters over 24 hours, adjusted based on how the body responds.
Most people begin to stabilize within a few hours of receiving hydrocortisone and fluids. Blood pressure recovers, nausea eases, and mental clarity returns. The speed of recovery, when treatment is given early, is one reason this condition is considered so preventable. The danger lies in delayed recognition.
Preventing a Crisis With Sick Day Rules
For people living with adrenal insufficiency, the most important tool for avoiding a crisis is knowing how to adjust their medication during illness or stress. These adjustments are called “sick day rules,” and every person on steroid replacement therapy should have them memorized.
The core principle is simple: when your body is under more stress than usual, it needs more cortisol than your normal replacement dose provides. The standard guidelines break down as follows:
- Fever above 38°C (100.4°F) or illness requiring bed rest: double your normal oral steroid dose
- Fever above 39°C (102.2°F): triple your normal dose
- Minor procedures like dental work: double the dose beforehand
- Vomiting, inability to keep pills down, severe illness, or trauma: use an emergency injection
These increased doses should continue for at least 72 hours. If you’re not improving after three days, it’s time to contact your doctor. There’s no need to adjust your mineralocorticoid dose (the medication that manages salt and water balance) during sick days.
The Emergency Injection Kit
Every person with known adrenal insufficiency should carry an emergency injection kit at all times. The kit contains a pre-measured dose of injectable hydrocortisone, a syringe, and alcohol wipes. The injection is designed to be given into the outer thigh muscle, similar to how an epinephrine auto-injector works for severe allergies.
The kit matters most in situations where you can’t take oral medication, whether because of vomiting, loss of consciousness, or a sudden injury. Family members, partners, and close coworkers should know where the kit is stored and how to administer the injection. Many people also wear a medical alert bracelet or carry a card identifying their condition, so emergency responders know to give hydrocortisone even if the person can’t communicate.
Keeping extra oral steroids on hand is equally important. Running out of medication, even for a day, can be enough to trigger a crisis in someone whose adrenal glands produce little or no cortisol on their own.