Diabetes is the most common disease affecting the pancreas. Type 1 diabetes (there are two types) is caused by insufficient insulin secretions. It is not a new disorder: during the Middle Ages, this disorder was described as the "pissing evil", almost two thousand years ago it was documented at causing "the melting of flesh into urine", and the original name given to this disease diabetes mellitus actually means the "flowing of honey". Why do these older ways of describing diabetes relate it to pissing, melting flesh, and honey? In order to answer that, we need to look at the physiology of the disease. You may also recall me having said that diabetes is a disorder in which the patients eat a lot, drink a lot, and pee a lot.
First, some background information. Insulin is required for glucose to enter most cells of the body. As most cells in the body rely on glucose for their energy, they rely on insulin to facilitate the entry of their precious energy source. Diabetes in an autoimmune disease in which the body attacks its own insulin-making cells (beta cells of the islets of Langerhans) within the pancreas.
Now let's get to the nitty-gritty details of what happens when the body doesn't have insulin. Without insulin, the cells of the body think they are energy-starved because they can't get any of the glucose present in the blood stream. As a result, the body breaks down muscle proteins in order to gain energy. Moreover, the fat stored in the body will also be broken down to give the cells energy. These two combined explain the melting flesh description. Without treatment, diabetics will appear to "waste away". In addition, when fat is broken down ketones are made. Ketones are volatile and smell sweet. They leave the body through breath, which is why diabetics can have sweet smelling breath.
Since glucose is not able to leave the blood and enter cells without insulin, it builds up in the blood, causing hyperglycemia. Parts of the brain, including its satiety (or "fullnss" center) require glucose. Without any glucose entering the satiety center, the body never feels full and is always hungry, despite regular eating. Which explains the eating a lot.
With all of the excess glucose floating around, the renal (aka kidney) threshold for glucose is reached and glucose starts being urinated out. The urine will thus have a sweet smell and syrupy nature. Hence the reference to honey urine. Also, when the glucose leaves the body in urine, it attracts water and brings it with it. Thus, untreated diabetics will have to pee a lot. Which explains the pissing reference. As a result of all this excess urination, diabetics will tend to be very thirsty and will drink a lot. Without drinking a lot, diabetics can become dehydrated.
Well, there you have it. A brief explanation of the physiology behind the symptoms experienced by an untreated Type 1 Diabetes Mellitus patient.