Causes.—­Hereditary influences play an important role and cases are on record of its occurrence in many members of the same family.  Men are more frequently affected than women, the ratio being about three to two.  Persons of a nervous temperament are often affected.  It is a disease of the higher classes.  Hebrews seem especially prone to it.  The disease is comparatively rare in the colored race; women more than men in the negro,- nine to six.  In a considerable proportion of the cases of diabetes the patients have been very fat at the beginning of or prior to the onset of the disease.  It is more common in cities than in country districts.  The combination of intense application to business, over-indulgence in food and drink, with a sedentary life, seem particularly prone to induce the disease.  Injury to or disease of the spinal cord or brain has been followed by diabetes.  It is much more frequent in European countries than here.  Acute and chronic forms are recognized in the former.

Symptoms.—­The only difference is that the patients are younger in acute forms, the course is more rapid and the wasting away is more marked.  The onset of the disease is gradual and either frequent passing of urine (six to forty pints in twenty-four hours) or inordinate thirst attracts attention.  When it is fully established, there is great thirst, the passage of large quantities of sugar urine, a terrible appetite, and, as a rule, progressive emaciation.  The thirst is one of the most distressing symptoms.  Large quantities of water are required to keep the sugar in solution and for its excretion in the urine.  Some cases do not have the excessive thirst; but in such case the amount of urine passed is never large.  The thirst is most intense an hour or two after meals.  The digestion is generally good, but the appetite is inordinate.  Pain in the back is common.  The tongue is usually dry, red and glazed, and the saliva is scanty.  The gums may become swollen.  Constipation is the rule.  The skin is dry and harsh and sweating rarely occurs.  The temperature is under normal.  In spite of the enormous amount of food eaten a patient may become rapidly emaciated.  Patients past middle life may have the disease for years without much disturbance of the health; on the other hand I have seen them die after that age.  Progress is more rapid the younger the person.  Death usually occurs from coma of diabetes.  This is most common in young patients.

[Constitutional diseases 329]

1.  There is a sudden onset after exertion of weakness, feeble pulse, stupor, coma, death in a few hours.

2.  Sudden headache, coma, death in a few hours.

3.  After nausea, vomiting or a lung complication, there are headache, delirium, abdominal pain, rapid labored breathing, sweetish odor of the breath, stupor, rapid feeble pulse, coma and death within a few days.

Recovery.—­Instances of cure in true diabetes are rare.