Sick Day Rules for Addison's Disease: Hydrocortisone Stress Dosing, Step-by-Step Protocols

What Are Sick Day Rules and Why Do People With Addison's Disease Need Them?

Sick day rules are a set of dose-adjustment instructions that people with primary adrenal insufficiency follow during physical stress. A healthy adrenal gland can raise cortisol output from a baseline of roughly 10 to 20 mg/day to 75 to 150 mg/day during severe illness. People with Addison's disease cannot do this at all, which means any stressor that raises cortisol demand above what their replacement dose provides can trigger adrenal crisis, a life-threatening emergency with hypotension, hyponatremia, hyperkalemia, and shock.

Adrenal crisis carries an estimated mortality of 0.5 events per 100 patient-years and accounts for up to 6% of deaths in patients with known adrenal insufficiency, according to a 2016 analysis published in the European Journal of Endocrinology [1]. A separate German registry study of 883 patients found a crisis rate of 8.3 per 100 patient-years [2]. These numbers make clear that inadequate sick day management is not a theoretical risk. It is the leading preventable cause of death in this population.

The Society for Endocrinology, the Endocrine Society, and the European Society of Endocrinology all publish guidelines requiring that every patient with adrenal insufficiency receive explicit written sick day instructions and training in self-injection at diagnosis [3][4].

The Three-Tier Sick Day Dosing Protocol

Sick day rules for Addison's disease divide into three tiers based on illness severity. Each tier has a specific dose adjustment and a clear trigger.

Tier 1: Double the Daily Dose

Use this for fever above 38°C (100.4°F), minor infections such as a urinary tract infection or upper respiratory illness, routine dental extractions, or significant emotional stress lasting more than one day. If your baseline is 20 mg hydrocortisone daily (for example, 10 mg on waking and 5 mg at midday and 5 mg at 4 pm), increase to 40 mg spread across the same three doses. Continue doubling until the fever has resolved for 24 hours, then return to baseline [5].

The Endocrine Society's 2016 clinical practice guideline specifically recommends two-to-three-fold dose increases during febrile illness, noting that "patients should be instructed to double or triple their glucocorticoid dose" for intercurrent illness [4].

Tier 2: Triple the Daily Dose

Use this for moderate infections such as influenza, pyelonephritis, or gastroenteritis where vomiting is not yet constant but nausea is significant, moderate trauma such as a fracture or laceration requiring sutures, or surgical procedures performed under local anesthesia. A baseline of 20 mg becomes 60 mg, divided across the day. If an antiemetic such as ondansetron 4 mg controls nausea sufficiently to keep oral medication down, this tier is appropriate. Monitor blood pressure and hydration closely [4][5].

Tier 3: 100 mg Intramuscular Injection

This is the emergency tier. Persistent vomiting preventing oral intake, diarrhea causing rapid dehydration, loss of consciousness, severe hypotension, major trauma, or general anesthesia all require an immediate injection of 100 mg hydrocortisone sodium succinate given intramuscularly, followed by immediate hospital transfer. This dose is supported by the Society for Endocrinology's consensus statement and the European Society of Endocrinology's guidelines for adrenal crisis management [3][6].

A 2019 Cochrane review on glucocorticoid dosing during physiological stress confirmed that parenteral hydrocortisone 100 mg is the accepted standard for acute adrenal crisis in adults [7].

How to Administer the Emergency Hydrocortisone Injection

Every person with Addison's disease should own and know how to use a pre-filled emergency hydrocortisone injection kit. In the United States, Solu-Cortef (hydrocortisone sodium succinate) 100 mg Act-O-Vial is the standard option available by prescription [8]. In the United Kingdom, the NHS provides Efcortesol (hydrocortisone sodium phosphate) 100 mg/mL ampoules.

The injection is given intramuscularly into the outer thigh or deltoid. Subcutaneous injection is acceptable if the patient cannot reach the thigh and no other person is present, though intramuscular absorption is faster [3]. Partners, family members, or caregivers should receive training from the prescribing clinician or a diabetes-and-endocrinology nurse specialist.

Steps for self-injection with the Solu-Cortef Act-O-Vial:

1. Mix the vial by pressing the stopper until the powder and diluent combine.
2. Draw the full 2 mL into the provided syringe.
3. Inject into the outer mid-thigh (through clothing if necessary in a true emergency).
4. Call emergency services (911 in the US) immediately after or simultaneously.
5. Show the paramedics your steroid emergency card.

The injection buys time. It does not replace hospital assessment, intravenous fluids (typically 1 liter of 0.9% saline in the first hour), and ongoing IV hydrocortisone infusion at 200 mg per 24 hours [6][9].

Recognizing Adrenal Crisis Before It Becomes Life-Threatening

Adrenal crisis can escalate from prodrome to cardiovascular collapse within hours. Recognizing early warning signs allows Tier 2 or Tier 3 action before the situation becomes irreversible.

Early signs include unusual fatigue disproportionate to the illness, nausea, abdominal pain, dizziness on standing (orthostatic hypotension), and confusion or difficulty concentrating [9]. A study in the Journal of Clinical Endocrinology and Metabolism (N=444 patients with adrenal insufficiency) found that nausea and fatigue preceded frank crisis in 72% of cases, providing a window of at least 2 to 6 hours for intervention if recognized early [10].

Later signs indicating immediate injection and emergency transfer: blood pressure below 90/60 mmHg, persistent vomiting, cold and clammy skin, altered consciousness, and inability to stand [6]. Do not wait for laboratory confirmation. Give the injection first.

Sick Day Rules for Specific Scenarios

Surgery and Invasive Procedures

The perioperative stress dose protocol differs by surgical magnitude. Minor procedures under local anesthesia require 25 to 50 mg hydrocortisone IV at induction. Moderate surgery requires 50 to 75 mg IV at induction followed by 25 mg every 8 hours for 24 to 48 hours. Major surgery (cardiothoracic, abdominal) requires 100 mg IV at induction followed by 50 mg every 8 hours for 48 to 72 hours, then a rapid taper back to the patient's normal oral replacement dose over 1 to 3 days [4][11].

These recommendations align with those published in Endocrine Practice, the journal of the American Association of Clinical Endocrinologists, in their 2020 perioperative management guidelines [11].

Gastroenteritis and Vomiting

Gastroenteritis deserves special attention because vomiting directly prevents oral hydrocortisone absorption, collapsing the safety margin faster than almost any other common illness. At the first episode of vomiting, give an antiemetic (ondansetron or prochlorperazine suppository) and attempt oral hydrocortisone within 20 minutes. If a second episode of vomiting occurs within one hour, inject 100 mg hydrocortisone IM and call for help. Do not wait for a third episode [3][5].

A 2021 paper in Clinical Endocrinology analyzing precipitants of adrenal crisis in 515 events found gastrointestinal illness to be the trigger in 46% of cases, the single largest category [12].

Fever in Children With Adrenal Insufficiency

Children with Addison's disease follow the same doubling rule but require weight-based dosing. The standard replacement dose in children is approximately 8 to 10 mg/m² body surface area per day. During illness, this is doubled or tripled. The emergency injection dose for children is 50 mg hydrocortisone IM for those weighing <25 kg and 100 mg for those weighing 25 kg or more [13]. Parents should rehearse injection technique with their pediatric endocrinologist at every annual review.

Dental Procedures

Simple check-ups and cleaning require no dose change. Extractions or procedures expected to last more than 45 minutes require doubling the morning dose on the day of the procedure and taking the next scheduled dose at the normal time [5]. Procedures involving IV sedation follow the minor surgery protocol above.

Heat Exposure, Exercise, and Travel

Extreme heat and prolonged strenuous exercise both raise cortisol demand. Adding 5 mg hydrocortisone before an intense workout lasting more than 60 minutes or before extended outdoor activity in temperatures above 35°C is reasonable based on current guidance from the Society for Endocrinology [3]. Long-haul travel across multiple time zones should be discussed with the prescribing physician in advance to plan dose timing adjustments.

Tapering Back to Baseline After Illness

Returning to the normal replacement dose too slowly risks the side effects of even short-term excess glucocorticoid exposure: sleep disruption, elevated blood glucose, and fluid retention. Returning too quickly risks under-replacement if the illness has not fully resolved.

The standard approach: once the patient has been afebrile for 24 hours, is tolerating food and fluids, and feels near baseline, reduce from the sick day dose back to normal over 2 to 3 days by halving the excess each day [4]. For example, a patient who was on 60 mg/day (triple dose) would go to 40 mg on day one of taper, then 20 mg on day two, then resume their normal regimen. This is not the same as the prednisone tapering protocol used after courses of pharmacological steroids for inflammatory conditions, where the dose starts much higher and the adrenal axis suppression may last weeks to months.

Tapering Prednisone Safely: Key Differences From Hydrocortisone Replacement

Some patients with Addison's disease use prednisone or prednisolone instead of hydrocortisone, and others may be prescribed a course of pharmacological-dose prednisone on top of their replacement for an unrelated condition such as asthma or rheumatoid arthritis. These scenarios require different tapering logic.

Pharmacological prednisone at doses above 20 mg/day suppresses the hypothalamic-pituitary-adrenal axis within days. For a patient with already absent adrenal function, the risk is somewhat different: their baseline is already suppressed, but the abrupt withdrawal of high-dose prednisone still risks acute glucocorticoid deficiency because the prescribed dose was covering both replacement and pharmacological needs.

The general principle endorsed by the American College of Rheumatology is to taper no faster than 10% of the total daily dose per week once below 20 mg/day prednisone, and no faster than 1 mg/week below 10 mg/day [14]. For Addison's patients specifically, the taper plan must be coordinated with the endocrinologist because the taper endpoint is not zero but the patient's established physiological replacement dose.

A 2020 review in Annals of Internal Medicine covering HPA axis recovery after prolonged glucocorticoid use noted that axis recovery after doses above 20 mg prednisone daily for more than three weeks could take three to twelve months in patients with intact adrenal glands, a timeline that is irrelevant for true Addison's patients but critically relevant for those with secondary adrenal insufficiency managed alongside Addison's protocols [15].

Stress Dose Protocols for Secondary and Relative Adrenal Insufficiency

Patients with secondary adrenal insufficiency (caused by pituitary disease or prolonged exogenous steroid use) follow broadly similar sick day rules, with one key difference: aldosterone secretion is usually preserved because the renin-angiotensin-aldosterone axis does not depend on ACTH. This means fludrocortisone supplementation is typically not required. The hydrocortisone sick day escalation, however, is identical [4][16].

Patients on pharmacological glucocorticoids for inflammatory disease (relative adrenal insufficiency) who undergo surgery or severe illness should receive supplemental hydrocortisone based on the same perioperative tiers outlined above, because their endogenous stress response may be blunted even if not absent [11][16].

The Emergency Steroid Card and Medical Alert Identification

Every patient with adrenal insufficiency should carry a steroid emergency card at all times. In the UK, NHS England mandated a standardized steroid emergency card in 2020 following a national patient safety alert [17]. In the US, the Addison's Disease Self-Help Group recommends a card stating the diagnosis, current medications and doses, and the instruction: "In emergency, give hydrocortisone 100 mg IV or IM immediately. Do not delay for laboratory results."

A medical alert bracelet or wristband stating "Adrenal Insufficiency. Give hydrocortisone in emergency" provides a backup when the patient cannot communicate [3]. Studies of emergency department management of adrenal crisis show that delays in corticosteroid administration are more common when patients arrive unconscious and without identification [18].

The HealthRX Sick Day Decision Framework below consolidates the three tiers into a single bedside reference that patients can print and attach to their medication kit.

HealthRX Sick Day Decision Framework for Addison's Disease

| Situation | Action | When to escalate | |---|---|---| | Fever >38°C, minor infection, dental extraction | Double daily hydrocortisone dose | If not improving in 24 hours, move to Tier 2 | | Moderate infection, controlled nausea, minor surgery | Triple daily hydrocortisone dose | If vomiting begins, move to Tier 3 immediately | | Vomiting, collapse, major surgery, severe injury | 100 mg hydrocortisone IM injection + call 911 | Hospital transfer required; do not manage at home | | Post-illness recovery (afebrile, tolerating food) | Halve excess each day over 2 to 3 days | If symptoms recur, return to Tier 1 dosing |

What Patients Should Tell Emergency Department Staff

Emergency physicians who do not regularly treat adrenal insufficiency may not automatically recognize an impending crisis or understand the urgency of steroid administration. A 2022 survey of 312 emergency medicine residents published in the Journal of the Endocrine Society found that only 41% correctly identified the first-line dose for adrenal crisis as 100 mg hydrocortisone IV [19]. Patients and families should state clearly:

• "I have Addison's disease. I am in adrenal crisis."
• "I need 100 mg hydrocortisone IV now."
• "I also need IV saline for fluid replacement."
• "Do not delay treatment for test results."

The Endocrine Society's 2016 guideline states explicitly: "Treatment should not be delayed for confirmatory laboratory testing in a patient with suspected adrenal crisis" [4].

Monitoring and Follow-Up After a Sick Day Event

Any sick day event requiring Tier 3 management (injection plus emergency care) warrants a follow-up appointment with the endocrinologist within one to two weeks. This visit should review whether the patient recognized warning signs early enough, whether the injection kit was accessible and the technique was correct, and whether the emergency card was up to date [3][5].

Patients who experience more than two crisis events per year should be evaluated for other factors: inadequate baseline replacement, comorbid conditions increasing cortisol demand (autoimmune thyroid disease is present in approximately 20% of Addison's patients), medication interactions reducing hydrocortisone absorption, or suboptimal dosing timing [20].

Annual sick day rule re-education is recommended in both the Society for Endocrinology consensus and the Endocrine Society guidelines. Verbal instruction alone is insufficient. Written action plans, injection technique demonstration, and a designated emergency contact person improve outcomes [3][4].