As an effete humor, Choleric pathologies aren't so much those of deficiency, but rather of excess, aggravation and morbidity.  Unfortunately, the abuses of modern life, especially dietary, give plenty of opportunities for this aggravation and morbidity to occur. 
     Yellow bile, being hot and dry, is most prone to aggravations of excess heat.  Most specifically, this refers to oxidation, which is a burning or charring of the humor by excess metabolic heat.  Heat and dryness can also unduly thicken or solidify bile, causing stagnation, obstruction and stone formation. 
     Yellow bile can also be amalgamated with, or corrupted by, other humors.  Of these, phlegm is the most common offender.  Morbid forms of yellow bile are also produced as a breakdown product from the putrefaction of blood.  Yellow bile, if charred or oxidized enough, will be burnt black and turned into morbid black bile.
     Yellow bile is hot, sharp and caustic; it is also light, subtle and penetrating.  Its subtle vapors can penetrate every nook and cranny of the organism, causing sallow, jaundiced, feverish, irritable, inflammatory, choleric conditions on a systemic level, or anywhere in the body.

Choleric Excess, or Plethora

     Because yellow bile is an effete humor, deficiencies of it are rarely seen.  Excesses of it, however, are quite common.
     Causes:  Due to its inherent temperament, the Choleric humor can become aggravated due to hot, dry environmental conditions, and is easily provoked in the summer.  Those of a Choleric temperament are also prone to excesses and aggravations of yellow bile.
     The most common causes of yellow bile aggravation are dietary.  Unfortunately, the most frequent offenders are the much craved taste sensations of our fast food culture and the affluent diet: hot, spicy peppers and chilies, greasy fried foods, sharp aged cheeses, vinegar, tomato sauces, salty or sour foods, and some fermented foods.  Hard liquor consumption and the tobacco habit must also be included.  Excessive meat consumption, especially red meat, is another culprit, as is a high salt intake.
     Those of a Choleric temperament, who crave these taste sensations, are most strongly attracted to these choler aggravating foods.  They can't be content with a bland, monotonous diet, even if it is more healthy and wholesome. 
     The fast pace and high stress level of our modern lifestyle are also big aggravators of Choleric excess.  These include stress, sleep deprivation, and eating on the run.  Again, those of a Choleric temperament are most naturally drawn to this type of behavior. 
     Signs and Symptoms:  In studying the clinical manifestations of Choleric aggravation, we must distinguish between those pertaining to yellow bile in its gross, humoral form versus Choleric vapors and residues that can be transported through the vital fluids to affect any part of the organism, including even the brain, mind and emotions.  The signs and symptoms caused by the former will center on the middle GI tract and hepatobiliary system, whereas those caused by the latter will tend to be systemic, or can occur anywhere.
     The clinical signs and symptoms of Choleric excess, or plethora, are as follows:
     Mind:  Anger, impatience, irritability.  Forceful, agitated manner.  Hypertension, stress.  Insomnia, restless sleep.
     Head:  Frequent headaches, migraines.  Sore, red, bloodshot eyes.  Yellow, jaundiced eyes.  Dry, irritated nostrils, nosebleeds.
     Oral:  Red, rough, dry tongue, red around edges; ulcerations, yellow coat.
Red, inflamed, bleeding gums, gingivitis.  Bitter taste in mouth.  Cold sores.  Bad breath.  Excessive thirst.
     Hepatobiliary:  Jaundice, biliousness, fatty liver.  Hepatitis, hepatomegaly (liver enlargement).  Gallstones, cholecystitis, biliary dyskinesia and congestion.  Constipation with light or pale colored stools.  Distension and fullness below the ribs. 
     Digestive:  Intolerance for greasy, fried foods.  Stomach hyperacidity, acid reflux, acid indigestion; gastric and/or duodenal ulcers.  Giddiness, nausea; vomiting of yellow or green bile.  Abdominal fullness, pain on pressure.  Soft, smelly or burning stools. 
     Skin:  Red, sensitive skin.  Hives, rashes, urticaria.  Sallow complexion; jaundice with a bright yellow complexion.
     Blood:  Bleeding disorders, inflammatory conditions.  Hemorrhoids. 
     Urinary:  Dark, scanty urine; burning urination.
     Pulse:  Full, rapid, bounding pulse. 
     Dreams:  Of fire, lightning, fighting, yellow things. 
     Few, if any, will experience all of these signs and symptoms simultaneously.   The more of them you experience, and the more intense they are, the more severe the plethora. 
     Choleric excess accumulates first in the liver, gall bladder and hepatobiliary tract.  From there, it affects the stomach and duodenum, causing ulcers, hyperacidity, acid reflux, and reflux esophagitis.  Alternatively, aggravated bile can spread from the hepatobiliary tract downwards, into the small intestine and colon, to cause irritable bowel or soft, smelly or burning stools.  From the hepatobiliary system, Choleric vapors can spread systemically to affect any part of the body.
     Our modern diet and lifestyle give us many things to provoke or aggravate bile, but few things to subdue or pacify it.  Neither does modern medicine have much to offer in this regard.  The best ways to pacify and subdue aggravations of yellow bile and truly heal and balance the bilious humor lie in diet, nutrition and herbal medicine.

Choleric Deficiency

     Since yellow bile is a necessary and vital substance, essential to the proper nutrition and metabolism of the organism, it is possible to suffer from a deficiency of it.  But true deficiencies of bile are comparatively rare; in many cases where a deficiency is suspected, it isn't a true deficiency, but rather a blockage in its flow and metabolism. 
     Since Greek Medicine also includes other digestive secretions of the middle digestive tract as being under the influence of the Choleric humor, a Choleric deficiency also includes a lack or insufficiency of these other digestive secretions, which are much more commonly seen.  Many suffer from low stomach acid or pancreatic enzymes.  Since the Digestive Force is the Administrative Virtue of the Choleric humor, a weak or flagging digestion would be one of its cardinal symptoms. 
     A true deficiency of bile would result in the poor assimilation and metabolism of fats and lipids.  Surgical removal of the gall bladder, which is quite common, is a form of secondary or functional bile deficiency, since it leads to the wastage of much bile, which is excreted slowly and continuously by the liver directly into the intestines, even when no fatty foods for it to digest are present.  The net effect of gall bladder removal in most persons seems to be a gaining of weight and fat, since the bile that assimilates, metabolizes and excretes fats from the body can no longer be utilized efficiently.
     A Choleric deficiency could also manifest as a deficiency of the functions of Choleric residues in the blood:  poor exuberant or fine capillary circulation, sluggishness and torpor of the blood, and a weak or deficient inflammatory response. 

Qualitative Disorders of Yellow Bile

     The qualitative disorders of yellow bile can be broadly divided into two categories: dyscrasias and oxidations.  Of dyscrasias, the amalgamation of yellow bile with various morbid forms of phlegm predominate.  Oxidations are various forms and degrees of charring yellow bile into a morbid ash-like substance.
     The Phlegmatic corruptions of yellow bile tend to occur mainly through dietary abuses.  Oxidations of yellow bile tend to occur through a hyperactivity of the digestive and metabolic fires. 
     These two processes, dyscrasia and oxidation of yellow bile, need not be mutually exclusive.  Amalgamations of yellow bile with phlegm or other humors can subsequently be oxidized or burnt, to varying degrees.

Phlegmatic Corruptions of Yellow Bile  

     Yellow bile may be corrupted by various types of morbid phlegm.  Not only are phlegm and choler complimentary opposites in their basic qualities, but the amalgamation of sharp, caustic bile with cooling, lubricating phlegm can be seen as a protective response of the organism to soften and dilute bile's caustic, irritating nature.
     The cause of these Phlegmatic corruptions of yellow bile is most often dietary - the excess consumption of rich, moist, unctuous foods, which generate excess phlegm; and fatty greasy foods, which aggravate bile.  Either the excess phlegm and bile are generated together, or they're generated separately, and meet up later.
     Citron Yellow Bile is a corruption of yellow bile with watery, insipid phlegm or serous fluids.  It is a bright lemon yellow.  Citron yellow bile is a slow, dull irritant to the entire organism.
     Vitelline Bile is a dark or dull yellow, the color of egg yolk.  Its home is in the liver, gall bladder and middle digestive tract.  Vitelline bile is an amalgamation of bile with thicker, denser forms of phlegm; its nature is stagnating and obstructive. 
     Phlegmatic corruptions of yellow bile will be associated with signs of both heat and dampness: a sluggish digestion; a sallow, jaundiced complexion; stools that are soft and sticky, yellow and smelly; putrid flatulence is also common.
     Phlegm and bile amalgamate to the mutual detriment of both humors.  The Digestive Force of bile is dulled or weakened, while the moist, nourishing properties of phlegm and serum are compromised, and tainted with the caustic irritation of gall. 

Oxidized Forms of Yellow Bile

     Atrabilious Choler is the least harmful of the oxidized forms of yellow bile, and is a simple amalgamation of yellow bile with black bile.  In the liver, atrabilious choler can interfere with normal humor generation; in the blood, atrabilious choleric residues can fail to thin the blood properly, deranging its normal viscosity and clotting properties.
     Charred Gall is bile that has been baked, thickened and hardened by excessive heat and dryness.  Caustic and inflammatory, charred gall thickens and congeals in the gall bladder, causing gall stones.  Normally, the gall bladder draws nourishment from the bile it takes into itself, but charred gall is more of an irritant to the gall bladder than a nutrient, producing cholecystitis and a weak, irritable and colicky gall bladder.  Spasms and colic in the gall bladder can trigger or aggravate colicky and spasmodic conditions throughout the GI tract. 
     Sanguineous Choler is an oxidized form of yellow bile that's a breakdown product of blood putrefaction.  When blood putrefies, the rarefied part will be oxidized into sanguineous choler, while the denser oxidized residues separate out to form morbid black bile.  The toxicity of sanguineous choler is moderate.
     Leekgreen Bile is a moderately oxidized form of vitelline bile that's found mainly in the stomach.  Many consider it to be produced by the heat generated from the overconsumption of foods like garlic, leeks and onions.  It's light and penetrating, sharp and caustic, and quite toxic.  It's a bright yellowish green, the color of leek leaves.
     Verdegris Bile is another morbid type of bile found mainly in the stomach, but also in the liver and gall bladder.  It's also an oxidized form of vitelline bile, but more heavily oxidized than the leekgreen variety; therefore, it's more toxic.  Its color resembles that of the green rust or patina found on copper, brass or bronze.
     Modern medicine considers bile that colors the stools green to be basically a normal variant of bile.  But in Greek Medicine, green bile isn't considered to be healthy or normal; it shows the abnormal charring or oxidation of yellow bile.
     Adust Choler is the most oxidized form of yellow bile, and is therefore the most toxic.  It is extremely dark in color, like wood charred black.
     Morbid, oxidized forms of yellow bile first affect the liver and gall bladder, and secondarily the stomach, duodenum and small intestine.  From there, they can spread to affect any part of the organism. 
     Oxidized forms of bile, fats and cholesterol are responsible for a lot of arterial plaque formation and cellular damage caused by oxidized fats, or free radicals.  To get to the root cause of these insidious degenerative conditions, we must first cleanse and normalize the bile metabolism, replacing the morbid, oxidized forms of yellow bile with normal, healthy bile. 
     The relative strength of the signs and symptoms produced will vary according to the degree to which the bile has been charred or oxidized.  The more hot, toxic and charred the bile, the stronger and more vehement the symptoms.

Putrefaction of Yellow Bile

     Like any other humor, yellow bile can putrefy.  The basic causes and mechanisms of its putrefaction are quite similar to those of blood.  Excessive moisture can corrupt yellow bile and weaken its innate heat and immunity, and also its digestive force; this then allows a foreign microbe or metabolic agent to come in and consume it.  Chronic stagnation of bile can also create conditions favoring its putrefaction.
     When yellow bile putrefies, it generates a certain type of fever called a bilious fever.  Also called a tertian fever or a tertian ague, this intermittent fever is so called because it appears on every third day, since it takes yellow bile about three days to ripen, and its toxins passed off.
     The more serious and greater the rate of putrefaction, and the more virulent the microbe involved, the higher and more vehement the fever.  Whatever form the bilious fever takes, signs and symptoms of Choleric aggravation will be prominent. 
     Cholera, as its name suggests, is considered by Greek Medicine in its various forms to be due to a putrefaction of choler, or yellow bile.  Different forms of the disease will have varying degrees of severity, depending on the virulence of the microbe involved; Asiatic cholera can even be fatal.  The cardinal signs include vomitings, often of bilious matter, and rampant diarrhea, as the offending caustic choler irritates, inflames and causes drastic evacuations of the bowels.  This is usually followed by the stage of collapse, which may be fatal, as the innate heat and energy of the bilious Fire element has been drained from the body.