Often in genealogy a researcher encounters an archaic medical term used for the cause of death, or perhaps in a journal or family correspondence, this list is intended to aid with interpreting those terms.

Day fever - Fever lasting one day; sweating sickness.
Debility - Abnormal bodily weakness or feebleness; decay of strength. This was a term descriptive of a patient's condition and of no help in making a diagnosis. Lack of movement or staying in bed. Synonym: asthenia.
Decrepitude - Feebleness due to old age.
Delirium tremens - aka DTs; hallucination due to alcoholism.
Dengue - Infectious fever endemic to East Africa.
Dentition - Cutting of teeth, see teething.
Deplumation - Tumor of the eyelids which causes hair loss.
Diary fever - A fever that lasts one day.
Diptheria - An acute infectious disease caused by toxigenic strains of the bacillus Corynebacterium diphtheriae, acquired by contact with an infected person or a carrier of the disease. It was usually confined to the upper respiratory tract (throat) and characterized by the formation of a tough membrane (false membrane) attached firmly to the underlying tissue that would bleed if forcibly removed. In the nineteenth century the disease was occasionally confused with scarlet fever and croup.
Distemper - Usually animal disease with malaise, discharge from nose and throat, anorexia.
Dock fever - Yellow fever.
Dropsy - A contraction for hydropsy. Edema, the presence of abnormally large amounts of fluid in intercellular tissue spaces or body cavities. Abdominal dropsy is ascites; brain dropsy is hydrocephalus; and chest dropsy is hydrothorax. Cardiac dropsy is a symptom of disease of the heart and arises from obstruction to the current of blood through the heart, lungs, or liver. Anasarca is general fluid accumulation throughout the body.Edema (swelling), often caused by kidney or heart disease.
Dropsy of the Brain - Encephalitis.
Dry Bellyache - Lead poisoning.
Dyscrasy - An abnormal body condition.
Dysentery - A term given to a number of disorders marked by inflammation of the intestines (especially of the colon) and attended by pain in the abdomen, by tenesmus (straining to defecate without the ability to do so), and by frequent stools containing blood and mucus. The causative agent may be chemical irritants, bacteria, protozoa, or parasitic worms. There are two specific varieties: (1) amebic dysentery caused by the protozoan Entamoeba histolytica; (2) bacillary dysentery caused by bacteria of the genus Shigella. Dysentery was one of the most severe scourges of armies in the nineteenth century. The several forms of dysentery and diarrhea accounted for more than one-fourth of all the cases of disease reported during the first two years of the Civil War. Synonyms: flux, bloody flux, contagious pyrexia (fever), frequent griping stools.
Dysorexy - Reduced appetite.
Dyspepsia - Indigestion and heartburn. Heart attack symptoms; bad digestion.
Dysury - Difficulty in urination.

Eclampsy - A form of toxemia (toxins, or poisons, in the blood) accompanying pregnancy, characterized by albuminuria (protein in the urine), by hypertension (high blood pressure), and by convulsions. In the last century, the term was used for any form of convulsion.
Ecstasy - A form of catalepsy characterixed by loss of reason.
Edema - Nephrosis; swelling of tissues. see Dropsy.
Edema of lungs - Congestive heart failure, a form of dropsy.
Eel thing - Erysipelas.
Effluvia - Exhalations or emanations, applied especially to those of noxious character. In the mid-nineteenth century, they were called "vapours" and distinguished into the contagious effluvia, such as rubeolar (measles); marsh effluvia, such as miasmata; and those arising from animals or vegetables, such as odors.
Elephantiasis - Gross enlargement of the body, especially the limbs, due to lymphatic obstruction by a nematode parasite transmitted by mosquitoes; a form of leprosy.
Emphysema, pulmonary - A chronic, irreversible disease of the lungs, characterized by abnormal enlargement of air spaces in the lungs and accompanied by destruction of the tissue lining the walls of the air sacs. By 1900 the condition was recognized as a chronic disease of the lungs associated with marked dyspnea (shortness of breath), hacking cough, defective aeration (oxygenation) of the blood, cyanosis (blue color of facial skin), and a full and rounded or "barrel-shaped" chest. This disease is now most commonly associated with tobacco smoking.
Encephalitis - Swelling of brain; aka sleeping sickness.
Enteric fever - see Typhoid fever.
Enterocolitis - Inflammation of the intestines.
Enteritis - Inflations of the bowels.
Epilepsy - A disorder of the nervous system, characterized either by mild, episodic loss of attention or sleepiness (petittnal) or by severe convulsions with loss of consciousness (grand mal). Synonyms: falling sickness, fits.
Epitaxis - Nose bleed.
Erysipelas - An acute, febrile, infectious disease, caused by a specific group of streptococcus bacterium and characterized by a diffusely spreading, deep-red inflammation of the skin or mucous membranes causing a rash with a well-defined margin; Contagious skin disease, due to infection of the blood with vesicular bulbous lesions. Synonyms: Rose, Saint Anthony's Fire.
Extravasted blood - Rupture of a blood vessel.

Falling sickness - see Epilepsy.
Fatty Liver - Cirrhosis of liver.
Fits - Sudden attack or seizure of muscle activity.
Flux - An excessive flow or discharge of fluid like hemorrhage or diarrhea. see dysentry.
Flux of humour - Circulation.
French pox - Syphilis.
Furuncle - see boil.

Gangrene - Death and decay of tissue in a part of the body, usually a limb, due to injury, disease, or failure of blood supply. Synonym: mortification.
Gathering - A collection of pus.
Glandular fever - Mononucleosis (mono).
Gleet - see catarrh.
Goitre - Enlarged thyroid gland which affects body's metabolism.
Gout - Chronic metabolic disorder affecting the joints, associated with hypertension, uric acid in the blood and kidney disease, often associated with a rich and fatty diet (and red wine).
Gravel - A disease characterized by multiple small calculi (stones or concretions of mineral salts) which are formed in the kidneys, passed along the ureters to the bladder, and expelled with the urine. Synonym: kidney stone.
Grave's disease - Thryotoxicosis.
Great pox - Syphilis.
Green fever/sickness - Anemia.
Grippe/grip - Influenza like symptoms; the flu; influenza.
Grocer's itch - Skin disease caused by mites in sugar or flour.

Heart sickness - Condition caused by loss of salt from body.
Heat stroke - Body temperature elevates because of surrounding environment temperature and body does not perspire to reduce temperature. Coma and death result if not reversed.
Hectical complaint - A daily recurring fever with profound sweating, chills, and flushed Hectic Fever appearance, often associated with pulmonary tuberculosis or septic poisoning.
Hematemesis - Vomiting blood.
Hematuria - Bloody urine.
Hemiplegy - Paralysis of one side of body.
Hip gout - Osteomylitis.
Hives - A skin eruption of weals (smooth, slightly elevated areas on the skin) which is redder or paler than the surrounding skin. Often attended by severe itching, it usually changes its size or shape or disappears within a few hours. It is the dermal evidence of allergy. See the discussion under croup; also called cynanche trachealis. In the mid-nineteenth century, hives was a commonly given cause of death of children three years and under. Because true hives does not kill, croup was probably the actual cause of death in those children.
Horrors - Delirium tremens.
Hospital Fever - see typhus.
Hydrocephalus - Enlarged head, water on the brain; dropsy of the brain. see dropsy.
Hydropericardium - Heart dropsy.
Hydrophobia - Rabies; fear of water.
Hydrothroax - Dropsy in the chest. see dropsy.
Hypertrophic - Enlargement of organ, like the heart.
Hypertropy of heart - Enlarged heart.
Hysteria - Wild uncontrollable emotion, excitement, functional dusturbance of the nervous system.

Icterus - see jaundice.
Impetigo - Contagious skin disease charac terized by pustules.
Inanition - Exhaustion from lack of nourishment; starvation. A condition characterized by marked weakness, extreme weight loss, and a decrease in metabolism resulting from severe and prolonged (usually weeks to months) insufficiency of food.
Infantile paralysis - Polio.
Infection - The affection or contamination of a person, organ, or wound with invading, multiplying, disease-producing germs (such as bacteria, rickettsiae, viruses, molds, yeasts, and protozoa). In the early part of the last century, infections were thought to be the propagation of disease by effluvia (see above) from patients crowded together. "Miasms" were believed to be substances which could not be seen in any form, emanations not apparent to the senses. Such miasms were understood to act by infection.
Inflammation - Redness, swelling, pain, tenderness, heat, and disturbed function of an area of the body, especially as a reaction of tissue to injurious agents. This mechanism serves as a localized and protective response to injury. The word ending -itis denotes inflammation on the part indicated by the word stem to which it is attached, as in: appendicitis, pleuritis, etc. Microscopically, it involves a complex series of events, including enlargement of the sizes of blood vessels; discharge of fluids, including plasma proteins; and migration of leukocytes (white blood cells) into the inflammatory focus. In the last century, cause of death often was listed as inflammation of a body organ, such as brain or lung, but this was purely a descriptive term and is not helpful in identifying the actual underlying disease.
Intestinal colic - Abdominal pain due to bad or improper diet.
Intussusception - The slipping of one part within another, as the prolapse of one part of the intestine into the lumen of an immediately adjoining part. This leads to obstruction and often must be relieved by surgery. Synonym: introsusception.

Jail fever - see typhus.
Jaundice - Yellow discoloration of the skin, whites of the eyes, and mucous membranes, due to an increase of bile pigments in the blood - often symptomatic of certain diseases, such as hepatitis, obstruction of the bile duct, or cancer of the liver; Condition caused by blockage of intestines (common in newborn babies) Synonym: icterus.

Kidney Stone - see gravel.
King's evil - A popular name for scrofula. The name originated in the time of Edward the Confessor, with the belief that the disease could be cured by the touch of the king of England. Tuberculosis of neck and lymph glands.
Kruchhusten - Whooping cough.

Lagrippe - Influenza.
Lockjaw - Tetanus, an infectious disease affecting the muscles of the neck and jaw in which the jaw beomes firmlt locked. Untreated, it is fatal in 8 days. Synonyms: trismus, tetanus.
Lues disease - Syphilis.
Lues venera - Venereal disease; sexually transmitted disease (STD).
Lumbago - Back pain.
Lung fever - Pneumonia.
Lung sickness - Tuberculosis.
Lying in - Time of delivery of infant.