Passing Out / Amnesia

This topic addresses a patient who says they “passed out,” or had amnesia for a period of time, usually somewhat recently, but now they feel and look completely fine.  Exam is normal.  We have possible causes to sort through (see table below). For patients with Memory Loss, see that topic.

For the E.R. diagnostic work-up of a patient actively in coma, seizing, or highly confused, see the mnemonic “Vowel TIPS”.

Causes of Loss of Consciousness (LOC)

…………..Patient Fell to Floor  
Faint (a.k.a. Syncope)
Seizure (generalized, “Grand Mal”)
Transient Ischemic Attack (TIA)
Concussion  (from Head Trauma)
Conversion Reaction
……….Episode of Amnesia (without Fall)  
Complex-Partial Seizure
Dissociative State
Transient Global Amnesia


Brief Definitions of the Diseases (see links for more explanation)

Faint:  Sudden momentary drop of blood circulation to the brain.  Several kinds:
….. Vasovagal (due to emotions, certain body functions, hot room, etc.; may feel nausea / woozy)
….. Orthostatic (standing up too fast if dehydrated, on certain meds, have certain diseases)
….. Cardiac Arrhythmia
….. Other Heart Diseases (Coronary Artery Disease; Obstruction of Blood Flow out of Heart)
.…. Occurs with Turning Head (very rare)
Seizure (generalized):  Nerve transmission in brain goes haywire; massive short circuits
Transient Ischemic Attack (TIA):  Start of a stroke, that resolves quickly on its own
Conversion Reaction:  Psychological way for mind to escape intolerable situation
Hyperventilation:  Very fast breathing from Anxiety
Complex-Partial Seizure:  Unconscious weird behavior; short-circuit in one lobe of brain
Dissociative State:  Mind is so distracted (often traumatic memories), acts without awareness
Transient Global Amnesia:  Can’t retain new memories, like where they are, what they’re doing
Intoxication:  Alcohol; any substances; poisoning

We make the diagnosis 100% by the medical history.  Witnesses give crucial clues; unwitnessed LOC is much harder.  Our most likely diagnoses for someone who has passed out or lost consciousness are:

KEY CLUES  (we query witnesses if any, or glean as best we can):

Fell to (or Awoke on) the Floor

Duration of LOC on Floor:

  • <20 secs:  Faint
  • >1 min:  Seizure
  • >5 min:  Conversion Reaction


  • Rapid:  Faint; Conversion Reaction
  • Gradual transition from confused to aware (10-30 min):  Seizure

Patient Can Recall What Others Around Did During the Episode:   Conversion Reaction

Movements of Arms & Legs:

  • Stiff & Shaking:  Seizure (can occasionally occur briefly with simple Faint)
  • Flailing (random):  Conversion Reaction


  • Rolled back:  Seizure; Faint
  • Rapidly shake in one direction (aka “nystagmus”):  Seizure
  • Glazed:  Faint; Seizure
  • Clenched Shut:  Conversion Reaction


  • Sides of Tongue:  Seizure; maybe Faint
  • Tip of Tongue, Lips, hands, etc.:  Conversion Reaction

Triggers That Provoked the Event:

  • Environmental (ugly sight, smell, etc); Straining; Emotions:  Faint
  • Exertion:  Faint from Heart Disease
  • Confrontational or Situational Stress:  Conversion Reaction
  • Neck Movement (rare):  Faint; TIA (very rare)

Atherosclerosis (Heart Risks: old age, smoking, hypertension, diabetes, etc; see link)

Symptoms Just Before Collapse:

  • Aura (vague sensations like smell, flashing lights, etc.):  Seizure
  • Vertigo, Double Vision, Slurred Speech, Swallowing difficulty:  TIA

Face Turned Blue / Foamed at Mouth / IncontinenceSeizure

No Fall, but Loss of Awareness (Witnessed)

Strange Movements or ActionsComplex-Partial Seizure

  • grimace, lip-smack, chew, teeth clench, drool, swallow, blink
  • twitch shake, foot stomp, hand wave, tremor
  • stare, stiffen up
  • randomly walks around / runs / undresses
  • utters meaningless sounds

Patient Recall

  • Total amnesia of the episode:  Complex-Partial Seizure
  • Total loss of awareness during the episode:  Complex-Partial Seizure
  • Knew his/her name during the episode:  Transient Global Amnesia
  • Retained past memories during the episode:  Transient Global Amnesia

No Fall, episode of Amnesia  (Unwitnessed):  

We do tests to distinguish Complex-Partial Seizure vs. Dissociative State

  • Total Global Amnesia possible (if lasted 1-10 hours)
  • Intoxication possible
  • Can be impossible to distinguish


Tests we order depend on the reason we think a person passed out:

1.  If we suspect Faint (a.k.a. Syncope):

  • History suggests Vasovagal or Orthostatic Syncope  →   no tests
  • Faint during Exertion  →  EKG, Echocardiogram, maybe Stress Tests
  • Simply Faints  →  EKG
    • Cardiac Referral if EKG abnormal
  • Faints repeatedly when turns head a certain way (very rare)
    • Angiogram by MRI or CT; then Refer to Vascular Specialist
  • We send to ER if:
    • Same-day Faint with exertion
    • Same-day Faint + abnormal EKG or risks for Heart Disease

2.  If we suspect Seizure (any kind):

3.  If we suspect basilar artery Transient Ischemic Attack (TIA) [rare)]

4.  If we suspect a Conversion Reaction  →  no tests

  • We reassure patient it is a common psychological defense mechanism
  • If patient / family insist on “tests”   →  Refer to Neurology to decide

5.  If unwitnessed episode of Amnesia without a Fall

See Passing Out — Full Text for more in-depth explanations and discussions.


An Angiogram is essentially an x-ray or other image of an artery.  It’s performed by obtaining an image while dye, injected into the blood, is flowing through it.  This can be done invasively, which carries certain risks but obtains better information, or non-invasively, with no risks but an inferior picture.

An Arteriogram is the type of angiogram in which dye is injected directly into an artery.  For the coronary arteries, it’s the only type of angiogram possible (also called “Cardiac Catheterization,” or “Cath” for short).  An arteriogram is the clearest test to see the circulation in an area (brain, intestinal arteries), but runs an unlikely risk of causing stroke or tissue death there during the procedure.

A safer non-invasive image of arteries is by MRI- or CT-Angiogram.  Here dye is injected into a vein.  Then an MRI or CT scan takes images timed for when blood is expected to carry the dye to the organ.  But for some conditions, a plain angiogram (i.e. arteriogram) is necessary.

Terminology can be confusing, especially for the lung.  To rule out a Pulmonary Embolus, all that’s needed is the safer CT-Angiogram, since dye in a vein goes right into the pulmonary artery (see Diagrams: The Heart, and The Circulatory System).  However, for unusual cases or conditions it’s necessary to enter the pulmonary artery, the catheter will be threaded into it.

The various dyes used to inject carry some risk of kidney damage, but almost only in people who have poor kidney function to begin with.  Radiologists know how to deal with this if possible.

Transient Global Amnesia

Transient Global Amnesia (TGA) is a relatively newly-recognized condition, first identified in 1956.  It only occurs among people over 50 years-old, usually older.  For reasons not at all understood, a person loses their ability to form new memories.  They know their name and who they are, but don’t know how they got to wherever they are, and are confused about why they are doing whatever they’re doing, since they don’t recall what they’d just begun to do.

They also lose recent memories, and ask questions over and over, trying to understand what’s going on.  But older memories are preserved, so the patient retains all their previously-learned vocabulary.  They can dress, perform math, drive, play an instrument – anything they’d learned in the past.  The condition is extremely frightening; patients seek help however they can.

Patients are invariably taken to an ER, where all sorts of tests are done (see the mnemonic Vowel TIPS for how an ER addresses the symptom of “altered mental status,” i.e. confusion).  Everything is normal.  An MRI may detect various small findings, but none are diagnostic, so they can’t be interpreted.

TGA lasts from 1 to 12 hours (average is 6, by definition it’s <24).  Then it resolves on its own.  It would seem off-hand to be a form of stroke, seizure, migraine (without headache), or psychiatric phenomenon, but none of those causes are found.  The condition almost never recurs, so no treatment is available nor necessary.  Since we can’t help but wonder if such older persons might be at more risk of stroke, we make sure that any other diseases like diabetes or hypertension are well-controlled.  But we don’t even recommend aspirin, and we don’t restrict driving or other activities.

Dissociative State

By Dissociative State we mean the patient’s mind is so preoccupied that they are unaware of what they are doing at the time, and have complete amnesia for the episode.  The distracting factor is usually a traumatic memory.  A person would be aware enough not to hurt themselves, but nobody knows what actions they perform at the time, because they are invariably alone.  Anyone else present would likely cause them to “snap out of it.”

Essentially, a person comes for care because they “lost time.”  They experienced a period of amnesia they can’t account for; maybe multiple episodes.  There are many variants of Dissociative Disorder, some include what is sometimes referred to as “multiple personality disorder;” that’s not what we’re describing here.

It’s impossible for a clinician to distinguish  an unwitnessed psychiatric Dissociative episode from a Complex-Partial Seizure, given that both include amnesia for the event.  Since there are no tests to diagnose the former, we try to rule out the latter, by doing:

  • an MRI, looking for a possible brain tumor.  Seizures of any kind most often occur on their own, without tumors.  So no tumor doesn’t prove anything, but the presence of one would reinforce the likelihood it was a seizure; AND
  • An electroencephalogram (EEG) looking for abnormal brain waves suggesting predisposition to seizures.

Since Complex-Partial Seizures may come from abnormalities deep in the brain, sometimes a regular EEG is false-negative.  So we refer to Neurology to rule out the possibility (see link).

Here’s the best example I’ve seen personally (also described in Passing Out – Full Text).  A friend who’d been working abroad during a civil war, and was having episodes of amnesia, visited San Francisco, I ordered an EEG and MRI to rule out Seizure (both were normal).  A consulting Neurologist said there was no way to distinguish between the 2 conditions, leaned toward the latter since tests were normal & war is tough.  But I knew her situation abroad, which wasn’t particularly traumatic or dangerous.  It was only weeks later, before flying to Chicago, that she confided she was traveling to confront a brother who’d molested her in childhood.  Diagnosis: Dissociative Episodes.

Conversion Reaction

A Conversion Reaction is a sudden onset of symptoms which serve to escape an unbearable situation.  The person is not at all “faking it;” they have no conscious control of what they feel or do.  It’s different from “Factitious Disorder,” like Munchausen’s Syndrome, when patients consciously manufacture illness to gain attention or sympathy.  It’s also different from “Malingering,” which is simply a form of lying, in order to get something concrete, like disability or a school excuse.

Symptoms of Conversion Reaction can be almost anything, including blindness; coma, seizures; paralysis; inability to speak, walk, etc; virtually anything.  Some examples can be illustrative.

1. In my small Appalachian ER, a woman was brought in “comatose,” surrounded by worried family.  Not the first time; we knew her conversion reactions well, which occurred in the setting of major family arguments.  I asked the family [who were likely triggers] to please step out, and they said, “OK, but don’t stick needles in her.”  Huh?  Apparently the last time this happened, a temporary physician had tried to provoke a pain response [not a good way].  The patient was of course conscious, felt it, told her family after, but the psychological force was so strong at the time that she didn’t even react!

2. A 25-year-old man cam to the ER with “chest pain.”  I inquired what he was doing at the time: “Playing poker,” then mentioned a man who “raised him.”  Sounded interesting, and I used to play in high school, so I asked, “How much did he raise you;” it  turned out he was referring to the man who’d raised him as a child, a father figure.

This “father” had had a heart attack a month before, and now was losing heavily in the game.  So the patient developed chest pain, an unconscious attempt to get his “father” out of the game.  And “Dad” kept on playing another hour, with “son” clutching his chest, until finally driving him to the ER!

3.  One of my regular AIDS patients, first diagnosed far away during a brain infection, but now completely stable on HIV medications, was sent to me by a desperate outside neurologist “for brain surgery” [!!!!!].  The patient had new weakness, a CT scan showed a tumor, and the local neurosurgeon refused to operate because tumor location didn’t match neurological symptoms.  I sent him by phone to our local ER, which hospitalized him “with major neurological deficits.”

Neurology promptly discharged him, saying all his weakness was factitious, i.e. not real.  The “tumor” was nothing more than a scar from the old brain infection.  I saw him back a day later, and sure enough, on exam all his “weakness” was simply not real.  It wasn’t “faked,” he really felt weak, but his body was fine.

Then it turned out that his partner had just broken up with him, so this was his subconscious mind’s way of trying to salvage the relationship.  Didn’t work; and the partner, who’d come along during his visit with me, kept asking, “Do you think it might be all in his head?  Like, it’s all in his head? …”  I just hemmed and hawed, since treatment for Conversion Reactions is empathetic reassurance and frequent follow-up.  The partner kept going on, the patient sat quietly with a blank smile.

Post-Script:  The patient flew back to his very first hospital, they represcribed treatment for the original infection (potentially toxic, completely unwarranted), and the patient “miraculously” recovered.  I slowly discontinued those multiple medications, patient did fine; independently from all this, the 2 lovers reunited.

Conversion Reactions are challenging.

Seizures (Epilepsy)

A Seizure is an abnormal discharge of nerves in the brain, something like a short-circuit.  It can be caused by a wide variety of brain and other diseases (see the mnemonic Vowel TIPS for the many possibilities).  There are various kinds of Seizures (see below).

Epilepsy is a disease in which a person has recurrent seizures for no outside reason.  Presumably a microscopic abnormality in the brain is responsible.  There are many uncommon genetic conditions which may cause Epilepsy, but most patients have it all by itself.  Statistically, people with epilepsy are calculated to live 2 years less than those without; however, this factors in patients with rare types who may die significantly sooner.  As such, most people with epilepsy can expect to live normal life spans.  The term “seizure disorder” is synonymous with “epilepsy”.

Bystanders a frequently scared when someone has a seizure, and tend to withdraw.  Children with seizures may sadly be ostracized (community education is essential).  In ancient Greece and other societies, people with epilepsy were considered holy; oracles at the Temple of Delphi were thought to see the future during their seizures.

The vast majority of seizures last 1-2 minutes, then transition into a period of confusion, until the person gradually regains conscious awareness over 15-30 minutes.  “Status Epilepticus” refers to non-stop seizures, which can be life-threatening.  It’s defined as a seizure lasting over 5 minutes, or a second seizure that recurs before the person has fully regained consciousness.

Types of Seizures

Classification of seizures is now fairly complex.  The terms used here are old and out-of-date; but are simple and useful.  Current categories serve mainly neurologists; most health professionals are unfamiliar with them.  The following are seizure types which most clinicians would know of.

Generalized Seizure (“tonic-clonic”; “Grand Mal”)  —  This is the classic event we think of when we hear of a seizure. The person turns stiff, falls, arms and legs shake.  Eyes roll back or jerk to a side, mouth foams, person may bite their tongue or be incontinent.  Afterwards there’s the period of confusion, called post-ictal, until fully regaining consciousness.  The person has amnesia for the entire event.  There may be weird sensations just before the seizure (an aura) which might be recalled.  There may be partial or even full paralysis on one side of the body afterwards (“Todd’s Paralysis”), which may last over a day (usually less), goes away, and should not be confused with a stroke.

Complex-Partial Seizure  —  Begins with facial movements like grimacing, lip-smacking, chewing, teeth-grinding.  They the person begins random actions which may seem purposeful, but the person performs them completely unconsciously.  One blind patient of mine, accompanied by a health worker, walked to the clinic in the midst of a complex-partial seizure without the health worker even realizing anything abnormal.  Complex-partial seizures usually last less than 4 minutes, but the coming-to phase may be as long as 1-2 hours.  Sometimes a complex-partial seizure my turn into a generalized one.

Absence Seizures (“Petit Mal”)  —  brief spells of blank staring, lasting under 30 seconds, but may keep recurring.  More common among children.

Drop-Attacks  —  The body suddenly goes limp.  Since this can recur, the danger is that the person may hurt themselves.  Also more common in childhood, especially children with special neurologic conditions along with the epilepsy.

Myoclonic Seizures  —  Sudden jerks of one part of the body.  Patients with this usually retain consciousness.  If they begin in adulthood, they may be associated with brain tumors.

Febrile Seizures  —  Seizure with a fever, only in childhood.  Most of the time it’s a single event, suggesting the seizure is not due to the fever, but to a viral infection that also affects the brain.  Febrile seizures that recur in the future may simply be common epilepsy triggered by fever.  The most important part of a first febrile seizure isn’t treating the fever nor the seizure, but to make sure it’s not all due to meningitis.  Children with meningitis are sick; after the seizure resolves, they remain sick.  A child who bounces around happily after a febrile seizure won’t have meningitis.

What to Do for Someone Having a Generalized Seizure

The most important thing is to do nothing, sort of.  Bystanders trying to put stuff between the teeth get their fingers badly bitten.  If we measure blood gas during a seizure, we find results incompatible with life, yet the person wakes up and recovers fully!

It’s good to cradle the person’s head, so they don’t bang it on the ground.  The only time to try to protect someone is if they’re on the edge of a cliff or swimming pool, etc.  Nothing more.

Actually, a witness should immediately check their watch / cellphone and write the time down.  Seizures lasting over 5 minutes can be life-threatening, require medication to stop them.  Nobody can know how long a seizure lasts without specifically timing it.

Filming the seizure with your cellphone might be useful for future specialists.  You can find a way to send it to the person afterwards, or if an ambulance comes, have them alert an ER provider.

Should you call an ambulance if you see a stranger seize?  It would be common sense to, but some people with epilepsy may not want to receive expensive bills.  Before you call, check the person for a med-alert necklace or bracelet which might give an instruction.

Diagnosing Seizures

We order a brain MRI just to see if there’s a tumor present, even though seizures usually have nothing to do with them.  The main test used is the electroencephalogram (EEG), which can find abnormal brain waves.  The EEG is always positive during a seizure, and usually there’s some abnormality all the time, but sometimes not.  Neurologists may order tests like a portable continuous EEG. or admitting a patient to the hospital for a continuous EEG and simultaneous video recording.  In rare cases, it may be necessary to surgically insert an EEG probe deep in the brain to find abnormal nerve impulses.

Treating Seizures

There are many anti-epileptic drugs (a.k.a. anti-convulsants) available, often prescribed in combination.  If the first choice or choices don’t work, Neurologists go on to try others, and draw blood levels to be sure there’s enough of the medication in the body at all times.  The most extreme treatment, for people completely incapacitated by seizures, is to remove a lobe of the brain.  That sounds brutal, but is well-tolerated, and may allow a patient to lead a normal life.

Electroencephalogram (EEG)

The EEG is a machine to measure brain waves.  It’s mainly used to diagnose if somebody has had seizures (Epilepsy), and what kind of seizures they might be.  It’s not at all uncomfortable.

Sticky electrodes are placed on a person’s head, and a tracing is recorded (done with needles in the old days, but no more).  The test can be more accurate if the person is sleep-deprived.  Sometimes strobe lights and other accessories are used to stimulate brain areas that might generate seizures.  In rare cases when certain types of seizures are very frequent, but come from deep locations, it may be necessary to surgically place an electrode into the brain to obtain a closer recording.

EEGs can often detect abnormalities when a person feels well, but sometimes not.  However, the EEG is always diagnostic during a seizure.  Ambulatory (portable) EEGs may be used to obtain recordings over several days.  In cases that are difficult to diagnose and also disabling, a person may be admitted to a hospital for several days for a continuous EEG with simultaneous video-recording, to really understand what’s going on.  Interestingly, up to 40% of such patients’ abnormal spells are ultimately diagnosed as psychiatric illness, and not have epilepsy.

“Vowel TIPS” (mnemonic for Coma, etc.)

This is a mnemonic for diagnosing the different causes of acute coma, seizure, or confusion (a.k.a. Altered Mental Status). It’s useful when caring for patients in an E.R. setting.  The mnemonic stands for AE I O U T I P S (the 5 Vowels, plus TIPS).

A  –  Alcohol:  intoxication or withdrawal

  • Withdrawal can cause mild seizures on Days 2-3, or life-threatening Delirium Tremens (“DT’s”) on Days 4-5
  • Mnemonic “A” also includes brain damage from alcohol, or from liver Cirrhosis

E  –  Epilepsy  (i.e. Seizures, of any cause)

I   –  Infection:   Sepsis; Brain Infections (Meningitis, etc.)

O  –  Opiates  (i.e. also other drugs / medications)

U  –  Uremia (Kidney Failure) & Other Metabolic States

  • mnemonic here sort of cheats, because it includes many possibilities:
  • Liver, Thyroid, or Adrenal failure
  • High / Low blood levels of sodium, potassium, calcium, etc….

T  –  Trauma, Tumor

  • Brain masses, including bleeding, hydrocephalus (spinal fluid overload)

I   –  Insulin:  i.e. related to Diabetes

  • Hypoglycemia from medication
  • Diabetic coma (severe Hyperglycemia)
  • Diabetic Ketoacidosis

P  –  Psychiatric  (Conversion Reaction)

S  –  Shock, Stroke, Syncope, Suffocation

  • Lack of oxygen in the brain, various causes

Diagnostic Work-Up is obviously complex, including obtaining History from friends, family, & witnesses as possible (this is most important); Physical Exam; Tests such as:

  • Rapid Fingerstick for glucose (rule-out Hypoglycemia)
  • Complete Blood Count (CBC)
  • Comprehensive Metabolic Panel (CMP)
  • Urinalysis
  • Toxicology Screen (urine & blood, for drugs)
  • Blood gas analysis (levels of oxygen & acids)
  • Chest X-ray
  • EKG
  • CT scan of brain
  • Spinal Tap
  • Many more

Fainting (Syncope)

The medical term for “Faint” is “Syncope”.  It occurs when blood flow to the entire brain is suddenly reduced.  Most causes are obviously temporary, because if not, death ensues.  In many cases, the faint cures itself, because falling from standing to lying allows more blood to arrive.

General Causes of Syncope                    

  • Vasovagal Syncope
  • Orthostatic Syncope
  • Cardiac Arrhythmias
  • Other Heart Diseases
  • Neck Movement causing Syncope

Vasovagal Syncope: The Vagus Nerve runs from the brain down to the bowel and bladder, able to affect all the organs in between.  In terms of the heart, Vagal action slows the heart rate.  The prefix “vaso-“ means blood vessels, so when the heart suddenly slows, blood flow to the brain drops.

The Vagus Nerve can be stimulated in various contexts:

  • Emotional trigger: fear, pain, anxiety, laughter, disgust (sight of blood, etc.)
  • Reflex actions: cough, urination, defecation, swallowing (esp. cold liquid)
  • Straining: weight-lifting, horn-playing, etc.
  • Situations: crowded room, prolonged standing, heat, etc.
  • Digesting a heavy meal

If we think the patient had Vasovagal Syncope, we don’t do any tests.  Diagnosis is made by the history alone.  We just need to be comfortable that the person did not have Cardiac Syncope (see below).  Treatment is simple reassurance.

Orthostatic Syncope:  This means that blood pressure drops upon standing.  It may be provoked by:

  • Loss of blood volume (hemorrhage, dehydration)
  • Medications / Alcohol
  • Blood pressure instability from certain diseases (Diabetes, Parkinson’s etc.)

We don’t need any tests if fainting occurred in the past, and the patient feels fine now.  If symptoms of any sort persist, we measure Postural Vital Signs to confirm our suspicion (check heart rate and blood pressure lying down, and then upon standing; see link).

Treatment is patient education: if lying down, sit for a while before standing up; stand with caution, to be able to sit again if necessary.

Cardiac Arrhythmias:  Here the heart doesn’t pump efficiently due to an abnormal heart rhythm.  See the link for detailed descriptions of the various kinds.  In general, Arrhythmias may be:

  • Not so dangerous: Supraventricular Tachycardia (fainting is rare, but may occur at the very onset)
  • Life-Threatening: heart block, bradycardia, ventricular tachycardia, long QT

Diagnosis is by EKG, and various types of portable Ambulatory Heart Monitors.  Treatment depends on the type of Arrhythmia found (see link).

Heart Diseases (other):  We especially suspect these if Fainting occurs during exertion.  There may be other symptoms as well, such as chest pain, shortness of breath, nausea, or burst of cold sweat.  These diseases may be either:

  • Coronary Artery Disease (i.e. Heart Attack, or less serious Angina)
  • Outflow obstruction (interference with blood flow as it’s pumped from the heart) —Hypertrophic Cardiomyopathy, Tumors, Aortic Stenosis

Diagnosis of Coronary Artery Disease is by EKG, Stress Tests, and more.  See the link.  Diagnosis of Outflow Obstruction is by Echocardiogram.  Treatments depend on the underlying diseases.

Neck Movement causing Syncope may be from either:

  • Pressure on Vagus Nerve running next to the carotid pulse (slows the heart rate)
  • Unusual anatomy that occludes the carotid artery (causing TIA)

This is pretty rare.  Diagnosis is made by history, then by various imaging (x-rays, etc.) to seek anatomical abnormalities.


Leukemia is a blood cancer, specifically of our white blood cells (WBCs) (a.k.a. “leukocytes”), which are the major component of our immune system.  There are different types of WBCs (see link, and diagram below), thus there are different types of Leukemia, which can be either acute or chronic.  But even though the Leukemias are diseases of WBCs, the 2 other types of blood cells are also affected: Red Blood Cells (RBCs) and Platelets.

©Terese WinslowUS Gov’t has certain rights………

We see above that our primordial original Stem Cell in the bone marrow produces subsets: Myeloid Stem Cells and Lymphoid Stem Cells; both produce types of WBCs.  Most granulocytes are Neutrophils, the main actor of innate immunity, our first line of defense to immediately attack and destroy anything that enters our body like germs, splinters, etc. (see also link WBCs).  Lymphocytes comprise our adaptive immunity, which can remember germs that have previously invaded us, then produce antibody and other long-term protection from future infection. 

The Leukemias can be very complex; there are many different types, and all have additional sub-types.  Here we briefly outline the two main types: Myelogenous and Lymphocytic (see diagram above).  Either can be Acute or Chronic.  So the most common Leukemias are:

  • Acute Myelogenous Leukemia (AML)
  • Acute Lymphocytic Leukemia (ALL)
  • Chronic Myelogenous Leukemia (CML)
  • Chronic Lymphocytic Leukemia (CLL)

Acute Leukemias  (AML and ALL)

Similarities  —  Patients with AML & ALL may have the same symptoms.  These include:

  • Fevers
    • In AML, fever is usually from infection (maybe serious)
    • In ALL, fever may be from the leukemia itself
  • Shortness of breath (from Anemia)
  • Bruising or bleeding (from low Platelets)
  • Fatigue

Diagnosis can usually be suspected from a basic lab test Complete Blood Count (CBC), but must be confirmed by a bone marrow biopsy.  The latter is crucial for determining the subtype of AML or ALL, which guides choice of treatment and suggests the prognosis.  Most patients require intensive chemotherapy initially (“induction”), then ongoing chemotherapy courses.  Some benefit from bone marrow transplants, which might cure the disease but may themselves run a 10% risk of death.

Differences  — 

  • AML is much more aggressive than ALL.  Patients may die soon without treatment
  • Sepsis and Neutropenia (low neutrophils) occur more often in AML.
    • Normal Neutrophil count is 2,000-6,000
    • <1,000 raises concern; <500 is dangerous; <200 critical
  • ALL is much more common <18 years-old, while half of AML patients are >65
    • For both, the older the patient, the less successful treatment
  • Swollen lymph nodes, large liver, swollen spleen suggest ALL

Chronic Leukemias (CML and CLL)

CML and CLL involve different types of WBCs: granulocytes (esp. Neutrophils) and Lymphocytes, respectively (see above diagram, also WBCs).  Still, they have many Similarities:

  • Both tend to occur at older age; half of CML patients are >60 at time of diagnosis, with CLL half are >70.
  • Both tend to be discovered accidently when a CBC blood test is drawn for other reasons, and shows obvious abnormalities:
    • Very high Neutrophil count for CML, very high Lymphocyte count for CLL
  • While many patients have no symptoms at time of diagnosis, some may have weight loss, drenching sweats, fatigue, fevers
  • Both CML and CLL may cause enlargement of liver and/or spleen
  • Both tend to last for years without symptoms before suddenly becoming worse
  • Both can be managed well with treatment, which does not require the intensive type of chemotherapy with many side effects as is given for acute leukemias (AML and ALL).

Differences between CML and CLL:

  • Complete Blood Count (CBC):  With CML, there are very high neutrophil counts; also maybe high eosinophils, basophils, and platelets too.  With CLL, lymphocytes are very high; there may be low platelets (never with CML)
  • CML usually requires a bone marrow biopsy to confirm diagnosis and plan treatment; CLL usually does not
  • CLL often causes many swollen lymph nodes
  • CLL may occasionally cause an exaggerated skin reaction to bee stings or mosquito bites, providing a clue to diagnosis

Once again, in contrast with Acute Leukemias, the treatment for CML and CLL is not toxic, and is often very effective.