What is diabetic coma?

Diabetic coma is loss of consciousness occurring as a result of very high blood sugar. Its causes are similar in both type 1 and type 2 diabetes, but with the important difference that other abnormalities of the blood chemistry may contribute to the coma in type 1 diabetes. These other abnormalities occur as a result of the almost total lack of insulin that is present in type 1 diabetes. For this reason, while blood sugar is almost always very high in people with type 2 diabetes who are in diabetic coma, being several hundreds (of mg/dl) to 2000 or more, it can be less elevated in people with type 1 diabetes, sometimes as low as only 200 or 300. In the case of type 1 diabetes, diabetic coma can occur solely as a result of having insufficient insulin in the body (e.g., running out of or not taking one's insulin), while in the case of type 2 diabetes, there is almost always another stress to the body that precipitates the coma, such as infection, dehydration, etc. If the serious abnormalities of blood chemistry that led to diabetic coma are not corrected rapidly, death can occur. Although the derangements in blood chemistry are more complex and severe in type 1 diabetes than in type 2 diabetes, there is a higher mortality in type 2 diabetic coma because people suffering from it tend to be older, in less robust health, and with more cardiac risk factors. Also, additional symptoms of nausea, vomiting, and abdominal pain occur in the derangements of type 1 diabetes leading to coma and the diagnosis may be made earlier as a result. In the early stages of coma in type 2 diabetes, abnormalities of brain function and consciousness are more prominent due to the extreme degree of dehydration. Moreover, the illness that precipitated the coma may carry its own serious health risks. Although only a minority of patients with diabetes will succumb to coma, it remains an important medical emergency that requires immediate intervention.

Diabetic coma is loss of consciousness occurring as a result of very high blood sugar.

What is diabetic neuropathy?

Diabetic neuropathy is the term used to describe the usually chronic damage to nerves that occurs as a result of untreated, or inadequately treated, high blood sugar. It results from a complex sequence of events that leads to damage and destruction of the minute blood vessels that nourish nerves along their course to the region of the body they serve after leaving the spinal canal. Each such nerve is a single cell. The longest nerves, much like long chains, are the most susceptible to damage. If a peripheral nerve (i.e., a nerve cell not contained in the brain or spinal column) emerging from the spinal column and traveling to the toes were the thickness of a piece of string, it would be 3 miles in length! At frequent intervals along its length, each peripheral nerve receives nourishment from tiny blood vessels. If any of these tiny blood vessels are irreversibly damaged, that part of the nerve dies and no signals are conducted in either direction along it, i.e., the chain fails at its weakest link. Although there are a vast number of individual nerve fibers serving any one area of the body, when a sufficiently large number get damaged, symptoms will result. Since the longest nerve fibers serve the parts of the body that are farthest from the spinal column, it is not surprising that they are the ones most frequently damaged. Therefore, diabetic neuropathy is most frequently a problem in the feet, hands, and male genitals. The symptoms represent a spectrum from those due to injury responses of the non-fatally injured nerves, such as pain, burning, and abnormal sensations such as bunched socks under the feet, to those due to loss of impulses, such as numbness and unperceived injury due to loss of protective sensation. This includes inability to perceive heat and sharp pain, leading to burns and puncture wounds. Although the typical form of diabetic neuropathy causes these symptoms, there are a number of other less common forms that can lead to sudden pain, weakness, and other unsuspected symptoms in almost every region of the body. Discussion of the whole range of these is beyond the scope of this book.

Peripheral nerve

A nerve cell not contained In the brain or spinal column.

Diabetic neuropathy is most frequently a problem in the feet, hands, and male genitals.

Protective sensation

The perception of potential injury, such as awareness of sharp, rough, excessively hot or cold objects, or friction.