Adrenal Crisis and Stress Dose Interpreter
Adrenal Crisis and Stress Dose Interpreter
If you take a steroid to replace the hormone your adrenal glands cannot make, being ill changes what you need. Read this first: an adrenal crisis is treated straight away with an injection of hydrocortisone, and treatment is never delayed to wait for a blood test. If someone is collapsed, drowsy, confused, vomiting repeatedly or has severe abdominal pain, call emergency services now. This page tells you what the published guidance says; it is not a substitute for medical care and cannot manage a crisis for you.
Sick day rules: what should the dose be?
Stressor + dose + route → what the guidelines sayAn adult with primary adrenal insufficiency taking 20 mg of hydrocortisone a day — 10 mg on waking, 5 mg at lunchtime, 5 mg at 17:00. They have influenza with a temperature of 38.4 °C, are eating and drinking, and have an emergency injection kit at home.
The published doses, and where each one comes from
Fever above 38 °C — double the usual replacement dose until recovery, usually 2 to 3 days.
Fever above 39 °C — triple it.
Vomiting or diarrhoea — tablets are not absorbed. Parenteral hydrocortisone and intravenous fluids without delay.
Minor to moderate procedure — hydrocortisone 25 to 75 mg over 24 hours, usually 1 to 2 days.
Major surgery, trauma, delivery, intensive care — 100 mg intravenously, then 200 mg over 24 hours.
- why an injection and not a tablet
- because the commonest route into a crisis is an illness that stops tablets being absorbed. Vomiting and diarrhoea are the classic trigger, and a swallowed dose that comes straight back up is not a dose. An intramuscular injection into the thigh bypasses the problem entirely, which is why the Endocrine Society recommends that every patient should be equipped with a glucocorticoid injection kit for emergency use and be educated on how to use it
- never delayed for a test
- the Endocrine Society’s recommendation is graded strong: in patients with severe adrenal insufficiency symptoms or adrenal crisis, immediate intravenous hydrocortisone at an appropriate stress dose is given before diagnostic results are available, and treatment should not be delayed by awaiting the results of cosyntropin testing. The UK guidance says the same. A cortisol sample can be taken at the same moment as the injection if someone wants one; nothing waits for it
- double at 38, treble at 39
- the Endocrine Society’s wording is that hydrocortisone replacement doses are doubled above 38 °C or tripled above 39 °C until recovery, usually two to three days, with increased consumption of electrolyte-containing fluids as tolerated. UK practice teaches doubling whenever the patient is unwell, which fires earlier. The doses agree; the trigger does not, and this page prints both rather than picking
- spread across the day
- hydrocortisone has a short half-life, so tripling a single morning dose leaves the evening uncovered. The UK worked example for a patient on 15 mg a day or less shows the shape: 20 mg on rising, 10 mg at lunchtime, 10 mg at teatime, a total of 40 mg. More doses, closer together, rather than one large one
- the steroid emergency card
- the Endocrine Society recommends that all patients carry a steroid emergency card and medical alert identification, to tell health personnel of the need for increased glucocorticoid doses and for immediate parenteral steroid in an emergency. It works because it removes the need to explain anything at the moment you are least able to
- these are adult doses
- the paediatric figures in the same guideline are per square metre of body surface area — 50 mg/m² for the immediate dose and 50 to 100 mg/m² over 24 hours — and this page does not take a body surface area, so it does not attempt them. A child on replacement glucocorticoid needs their own written plan from their paediatric endocrine team
- if you do not take hydrocortisone
- almost every published figure here is in milligrams of hydrocortisone. The corticosteroid equivalent dose calculator already does the potency arithmetic between hydrocortisone, prednisolone, prednisone, methylprednisolone and dexamethasone, and this page deliberately does not repeat it. Note what does not convert: mineralocorticoid activity does not travel with glucocorticoid potency, which matters for fludrocortisone
Worked example
An adult with primary adrenal insufficiency taking 20 mg of hydrocortisone a day — 10 mg on waking, 5 mg at lunchtime, 5 mg at 17:00. They have influenza with a temperature of 38.4 °C, are eating and drinking, and have an emergency injection kit at home.
Temperature 38.4 °C is above 38 and below 39, so the Endocrine Society rule is to double, not treble
Twice 20 mg is 40 mg a day, kept in the same pattern: 20 mg on waking, 10 mg at lunchtime, 10 mg at 17:00
Keep it up until recovery, usually two to three days, and take extra fluids containing salt
Return to 20 mg a day once the fever has gone and they feel well again — no taper is needed after a short course
What would change the answer: a temperature reaching 39 °C would mean tripling to 60 mg a day. Vomiting would mean the tablets could not be relied on at all, and the injection kit and medical help would be the answer instead
And if they became drowsy, confused or collapsed, that is an adrenal crisis: emergency services, 100 mg of hydrocortisone by injection, and no waiting for a blood test
What to do, by situation
| Situation | What the guidelines say | Where it comes from |
|---|---|---|
| Unwell, no fever | UK: double if unwell. Endocrine Society: no change until 38 °C | The two differ — follow your own written plan |
| Fever 38 to 38.9 °C | Double the usual daily dose, 2 to 3 days | Endocrine Society 2016 |
| Fever 39 °C or above | Triple the usual daily dose, 2 to 3 days | Endocrine Society 2016 |
| Vomiting or diarrhoea | Injection, not tablets. Parenteral hydrocortisone and IV fluids without delay | Society for Endocrinology 2020 |
| Minor procedure or dental extraction | Hydrocortisone 25 to 75 mg over 24 hours, 1 to 2 days | Endocrine Society 2016, Table 3 |
| Major surgery, trauma, delivery | 100 mg IV, then 200 mg over 24 hours | Endocrine Society 2016, Table 3 |
| Suspected adrenal crisis | 100 mg hydrocortisone IM or IV immediately, then 200 mg over 24 hours with IV fluids. Call emergency services. | Both, independently, with the same numbers |
Signs that this has become an emergency
| Sign | Why it matters |
|---|---|
| Drowsiness or confusion | Suggests the circulation or the sodium is already affected |
| Collapse, or dizziness on standing | Low blood pressure from cortisol deficiency, made worse by fluid loss |
| Repeated vomiting | Tablets cannot be absorbed, so the problem cannot be fixed by mouth |
| Severe abdominal pain | A recognised presentation of adrenal crisis, and often mistaken for a surgical abdomen |
| Fever with shivering and a racing pulse | Sepsis is a common trigger and needs treating alongside the steroid |
Why being ill changes the dose, and why a tablet is sometimes not enough
A healthy adrenal gland responds to illness, injury and surgery by producing several times its usual amount of cortisol. That extra cortisol maintains blood pressure, keeps blood sugar up and supports the response to infection. A person whose adrenal glands cannot do this, or whose pituitary no longer drives them, takes a fixed replacement dose that is set for an ordinary day — so when an ordinary day becomes an illness, the dose has to be increased deliberately. That is what sick-day rules are.
The published rules are simple and the two main sources agree about the doses. The Endocrine Society’s 2016 guideline doubles the replacement dose for a temperature above 38 °C and triples it above 39 °C, for the two to three days an illness usually lasts, with extra fluids containing electrolytes. For a minor or moderate procedure it gives 25 to 75 mg of hydrocortisone over 24 hours for a day or two; for major surgery, trauma, childbirth or intensive care, 100 mg intravenously followed by 200 mg over 24 hours. UK guidance from the Society for Endocrinology gives the same figures for emergencies and surgery, and differs in one place: it teaches patients to double the dose whenever they are unwell, rather than waiting for a thermometer reading. That difference is printed on this page rather than resolved, because both positions are defensible and your own team’s written plan is the one that applies to you.
The situation where a tablet stops being the answer is vomiting or diarrhoea. UK guidance is explicit that patients with adrenal insufficiency are particularly at risk from these illnesses because they cannot absorb their oral steroids — a vomited tablet is not a dose, and someone who keeps trying tablets while getting worse is on the commonest path into an adrenal crisis. This is what the emergency injection kit is for. The Endocrine Society recommends that every patient should be equipped with one and taught to use it, together with a steroid emergency card and medical alert identification, and if you do not have those, asking for them is worth an appointment of its own.
An adrenal crisis itself is a medical emergency with a mortality that is not small. The treatment is 100 mg of hydrocortisone by intramuscular or intravenous injection, immediately, followed by 200 mg over the next 24 hours with intravenous fluids. Both sources are unambiguous that this is given before any diagnostic test: the Endocrine Society recommends immediate intravenous hydrocortisone prior to the availability of diagnostic results, and says treatment should not be delayed by awaiting the results of cosyntropin testing; the UK guidance says treatment should not be delayed while trying to make a diagnosis. If a cortisol sample is wanted, it can be taken from the same cannula at the same moment. Nothing waits for it.
Two pages carry related arithmetic. The corticosteroid equivalent dose calculator converts between hydrocortisone, prednisolone, prednisone, methylprednisolone and dexamethasone, which is needed because nearly every figure above is written in milligrams of hydrocortisone. The glucocorticoid withdrawal interpreter covers the different question of how to stop a glucocorticoid that was prescribed for an illness rather than as replacement, and the short Synacthen test interpreter covers the test used to establish whether the axis works at all.
Frequently asked questions
When should I double my steroid dose?
The Endocrine Society’s 2016 guideline doubles the hydrocortisone replacement dose for a temperature above 38 °C, and triples it above 39 °C, until recovery — usually two to three days — with increased intake of electrolyte-containing fluids. UK guidance from the Society for Endocrinology teaches doubling whenever the patient is unwell, which starts earlier and covers illnesses without a fever. The doses are the same; only the trigger differs. A mild cold in someone who is eating, drinking and up and about usually needs no change under either. Your own endocrine team’s written plan takes precedence over both. Doubling for a day or two carries very little risk, and under-dosing during an illness carries a lot.
What is the emergency dose of hydrocortisone for an adrenal crisis?
For an adult, 100 mg of hydrocortisone by immediate intramuscular or intravenous injection, followed by 200 mg over the next 24 hours — as a continuous intravenous infusion, or as 50 mg every six hours — together with rapid intravenous fluids, a litre of isotonic saline in the first hour. The Endocrine Society’s 2016 guideline and the UK Society for Endocrinology’s 2020 guidance give the same figures independently. Paediatric doses are calculated per square metre of body surface area and are not covered here. If you have an emergency injection kit and have been trained, the first 100 mg is the dose it contains — but call emergency services first or at the same time, and go to hospital even if you feel better afterwards.
Should treatment wait for a cortisol result?
No. This is one of the clearest statements in the guideline literature. The Endocrine Society recommends, as a strong recommendation, immediate intravenous hydrocortisone at an appropriate stress dose in patients with severe adrenal insufficiency symptoms or adrenal crisis, before diagnostic results are available, and states that treatment should not be delayed by awaiting the results of cosyntropin testing. UK guidance says that if adrenal insufficiency is suspected, prompt treatment should not be delayed by performing or waiting for diagnostic tests. If a cortisol and ACTH sample is wanted, it can be drawn at the moment of the injection and processed later.
What if I am vomiting and cannot keep tablets down?
Then tablets are not the answer and the situation is urgent. UK guidance states that patients with adrenal insufficiency are particularly at risk from diarrhoea and vomiting illnesses because they cannot absorb their oral steroids, and that anyone with persistent symptoms should attend hospital for parenteral hydrocortisone and intravenous fluids without delay. If you have an emergency injection kit and have been trained to use it, this is exactly what it is for: give the intramuscular injection into the outer thigh and then contact your doctor or attend hospital. If you do not have a kit, contact your doctor or an urgent care service now rather than waiting to see whether the vomiting settles, and call emergency services if you become dizzy, drowsy, confused or develop abdominal pain.
Do I need to taper back down after sick-day dosing?
No, not after a short course. The increase lasts as long as the illness does — the Endocrine Society describes it as until recovery, usually two to three days — and you go straight back to your usual replacement dose once the fever has gone and you feel yourself again. Tapering matters after weeks or months of supraphysiological glucocorticoid, which is a different situation with a different page: see the guidance on stopping a glucocorticoid taken as treatment rather than as replacement. A couple of days at double or triple a replacement dose does not suppress anything that was not already suppressed.
I take prednisolone, not hydrocortisone. How do I apply these numbers?
Nearly every published figure in this area is written in milligrams of hydrocortisone, so the arithmetic has to be done once. The corticosteroid equivalent dose calculator on this site converts between hydrocortisone, prednisolone, prednisone, methylprednisolone and dexamethasone using relative glucocorticoid potency, and this page deliberately does not duplicate it. Two cautions. Mineralocorticoid activity does not travel with glucocorticoid potency, so a conversion that gets the glucocorticoid dose right can still leave someone short of mineralocorticoid — which is why fludrocortisone is prescribed separately in primary adrenal insufficiency. And in an emergency, the drug given is hydrocortisone regardless of what you normally take, because it acts quickly and has the mineralocorticoid activity that is needed.
Related calculators
References
- Bornstein SR, Allolio B, Arlt W, Barthel A, Don-Wauchope A, Hammer GD, Husebye ES, Merke DP, Murad MH, Stratakis CA, Torpy DJ. Diagnosis and treatment of primary adrenal insufficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2016;101(2):364–389. doi:10.1210/jc.2015-1710. Adrenal crisis: "100 mg (50 mg/m2 for children) hydrocortisone" by "an immediate parenteral injection", then "200 mg (50–100 mg/m2 for children) of hydrocortisone/24 hours (via continuous iv therapy or 6 hourly injection)" with "rapid infusion of 1000 mL isotonic saline within the first hour". Fever: "Hydrocortisone replacement doses doubled (>38°C) or tripled (>39°C) until recovery (usually 2 to 3 d)". Table 3: minor to moderate surgical stress "Hydrocortisone, 25–75 mg/24 h (usually 1 to 2 d)"; major surgery "Hydrocortisone, 100 mg per iv injection followed by continuous iv infusion of 200 mg hydrocortisone/24h".
- Bornstein SR et al., same guideline: "In patients with severe adrenal insufficiency symptoms or adrenal crisis, we recommend immediate therapy with iv hydrocortisone at an appropriate stress dose prior to the availability of the results of diagnostic tests", and "Treatment should therefore not be delayed by awaiting the results of cosyntropin testing." Also: "We recommend that every patient should be equipped with a glucocorticoid injection kit for emergency use and be educated on how to use it", and that all patients carry "a steroid emergency card and medical alert identification".
- Simpson H, Tomlinson J, Wass J, Dean J, Arlt W. Guidance for the prevention and emergency management of adult patients with adrenal insufficiency. Clin Med (Lond). 2020;20(4):371–378. doi:10.7861/clinmed.2019-0324. "100 mg hydrocortisone by iv or im injection, followed by 200 mg hydrocortisone/24 h continuous iv infusion in glucose 5%/24 h, or 50 mg 6 hourly im". "If an adrenal crisis is being considered … treatment should not be delayed while trying to make a diagnosis." Patients "are unable to absorb their oral steroids" during diarrhoea and vomiting and need "parenteral hydrocortisone and intravenous fluids without delay". For those on 15 mg/day or less of hydrocortisone, a sick-day total of "40 mg a day: 20 mg on rising, 10 mg at lunchtime, 10 mg at teatime".
- Beuschlein F, Else T, Bancos I, Hahner S, Hamidi O, van Hulsteijn L, Husebye ES, Karavitaki N, Prete A, Vaidya A, Yedinak C, Dekkers OM. European Society of Endocrinology and Endocrine Society joint clinical guideline: diagnosis and therapy of glucocorticoid-induced adrenal insufficiency. Eur J Endocrinol. 2024;190(5):G25–G51. doi:10.1093/ejendo/lvae029. R 3.1A: oral glucocorticoids for minor stress with no haemodynamic instability. R 3.1B: parenteral glucocorticoids for moderate to major stress, procedures under general or regional anaesthesia, and where oral intake is not possible. R 3.2: in patients presenting with haemodynamic instability, vomiting or diarrhoea, adrenal crisis should be considered and treated with parenteral glucocorticoids and fluid resuscitation.
Medical Disclaimer: The tools and content provided here are for educational and reference purposes only. They are not intended to substitute for professional medical advice, diagnosis, or treatment. Clinical decisions should always be based on the comprehensive assessment of a qualified healthcare professional.