MIST is a format for a brief, structured handover of medical information about an injured or ill person. In military casualty movement, the letters commonly stand for Mechanism of injury, Injuries, Signs/Symptoms and Treatment. These groups tell the next helper or care provider what happened, how the casualty’s condition has developed and which interventions have already been performed. During the recovery of isolated personnel, the format helps pass on this information clearly when contact or a handover is possible.
What the four fields explain
The sequence moves from the cause through the problems identified to the current condition and care already given. It separates information that can easily become confused when looking at a casualty: an incident history is not an injury finding, a complaint is not a confirmed diagnosis, and a dressing in place does not establish that it remains effective.
| Field | Content and purpose |
|---|---|
| M – Mechanism | What caused the injury? Examples include a fall, blast or gunshot injury, with the known circumstances and time. This gives the next provider the context of the injury. For illness, this field can be used as Medical Complaint to report the main complaint and its onset, such as abdominal pain present for several hours. State the cause only when it is known. |
| I – Injuries | Which injuries have been identified, at which body site and on which side? For an ill person, include the known illness or problems identified so far. Label visible wounds, the casualty’s own complaints and medically confirmed findings accordingly. A suspected fracture remains a suspicion; unexamined areas remain unassessed. The next helper can distinguish known problems from gaps in the information. |
| S – Signs/Symptoms | What is the condition now? Signs are observed or measured findings; symptoms are complaints described by the casualty. Examples include responsiveness, abnormal breathing, pain and vital signs actually obtained. The time of measurement and subsequent changes show whether an entry still describes the present condition. “Speaks coherently” and “reports shortness of breath” provide different information. |
| T – Treatment | What was actually done, when, and with what observed result? Report interventions performed and the means used, including the site of any local intervention. For medications already given, include the known name, amount, route and time. An unsuccessful attempt or recurrent bleeding must remain clear so that the next provider does not rely on an effect that has only been assumed. |
Time, trends and unknown values
The time of the incident, the time of a measurement and the time of treatment describe different events. “Fall at 14:10” does not establish when a pulse reported later was obtained. The time a dressing or tourniquet was applied belongs to that particular intervention. State the time system used; in an international handover, local time and UTC can otherwise be several hours apart.
Without a watch or reliable recollection, report the uncertainty: “approximately an hour ago”, “time estimated” or “application time unknown”. Measurements must also reflect what is actually known. Blood pressure and oxygen saturation cannot be reported without the appropriate devices; a pulse that feels fast is not a counted heart rate. “Not measured” preserves that information better than a supposedly normal number.
A trend requires earlier and current information with their times. “Initially awake and speaking coherently, increasingly drowsy for about ten minutes” describes a change concealed by “casualty responsive”. When measurements are available, pass on the latest value and significant changes. Without monitoring equipment, clear observations still have value. Looking at the casualty does not justify a blanket report of “vital signs stable”.
Information an isolated person can preserve
An injured person can describe the incident, personal symptoms and self-aid already performed without being able to name medical findings. A companion adds what they personally observed. Make the origin of each statement clear: “he says he briefly lost consciousness” is the casualty’s account; “I witnessed the loss of consciousness” is an observation. A diagnosis confirmed before isolation can be reported; that does not establish a diagnosis for new complaints.
State when a complete examination has not been performed. “Wound on the right lower leg; other injuries not assessed” is more useful than “only a leg injury”. Abdominal pain can be reported as a complaint without asserting an internal injury or a particular disease. With limited medical knowledge, describe responsiveness and behaviour in plain terms. A clinical score belongs in the report only when the assessment is understood and has actually been performed.
When writing materials are available and the situation permits, record the information on a casualty card being carried or a legible note, then add subsequent changes. The note must remain linked to the correct casualty and travel with them. Moisture or smearing can make entries illegible; records separated from the casualty may be unavailable at handover. Writing must not displace an immediately necessary intervention or protection from a present threat.
A brief, understandable handover
At an actual contact, first establish which casualty the report concerns. Then give the essential information in the agreed M–I–S–T sequence. Lead with an acute change that requires immediate action. The receiver needs the current information and important developments, rather than an unchanged repetition of an earlier report. In a noisy transport vehicle, a written summary can support communication.
A simple fictional report without monitoring equipment might read:
“MIST for the casualty on this litter. M: fall approximately an hour ago, time estimated. I: wound on the right lower leg; other injuries not fully assessed. S: awake, speaks coherently, reports right leg pain; blood pressure and oxygen saturation not measured. T: wound dressed about forty minutes ago; no new visible bleeding since then. No medications given.”
At handover, pass on the available records and show important interventions on the casualty. Interventions that cannot be seen, especially medications already given, must be reported explicitly. Correct misunderstood sides, times or equipment before the helpers separate. At each subsequent actual handover, update the report with new complaints, changes in condition and interventions performed since the previous report.
Reporting, care and requesting transport
MARCH prioritizes the assessment and treatment of immediately life-threatening injuries. MIST organizes communication of the known incident, condition and interventions already performed. The reporting sequence therefore does not determine which treatment is needed first. Completing a MIST format must not hold up urgent care.
The US Army’s 9-Line MEDEVAC Request organizes transport-request information, including pickup location, contact, patient numbers, transport needs and the situation at the pickup site. MIST adds medical information and is sent as soon as possible after that request; the evacuation mission should not wait for missing MIST information. A MIST report is not a complete transport request. For isolated personnel, locating, identity verification, access and physical pickup must also be arranged through the recovery procedures, forces and connections actually available.
Military use and ATMIST
German military casualty care uses MIST as Mechanism of injury, Injuries, Signs/Symptoms and Treatment. In the US en route care system, the same information groups structure the verbal handover, with written care records accompanying the patient. The US DD Form 1380 TCCC casualty card is also designed for non-medical first responders and records injury sites, time-linked vital signs and interventions performed. US military use also includes the field name Mechanism/Medical Complaint for M. An ill person’s complaints and their course can therefore be handed over without inventing an injury mechanism.
ATMIST is also used in the British clinical handover chain. In the North of Scotland trauma system, Age and Time precede the four MIST groups: age and time of the incident, followed by mechanism, injuries, signs and treatment so far. The incident time helps establish how long it has been since the injury; it does not replace the times of individual measurements or interventions. Additional pre-alert information, such as expected arrival and special requirements, remains separate.