Diabetes is a serious disorder of the body's metabolism, often resulting in a variety of complications, such as excessive thirst and urination, abnormal weight loss and fatigue. Even when treated with medication, a diabetic may still be excessively tired.

Incorrect Dosage

Although a diabetic may be taking medication to treat diabetes, the dosage may be inaccurate for his needs. If the dosage is incorrect, the person's blood glucose levels will likely become too high or too low, both of which result in fatigue.

Incorrect Medication

Similarly, the diabetes medication might simply no longer work for the person. This would likely cause a high level of blood glucose, which is the main cause of diabetes-related fatigue.

Side Effects

A variety of diabetes medications are available, and although each medication has the same ultimate purpose, they likely work in different ways. A side effect of certain medications may be fatigue, which would cause the person to sleep more than normal.

Dehydration

Dehydration commonly occurs in conjunction with diabetes, and may actually be exacerbated by the use of medications. A dehydrated body significantly impairs the functioning of the body, causing excessive fatigue.

Obesity

Many people with diabetes are overweight. Although obesity does not directly cause fatigue, it does reduce the person's desire to be active, which can lead to tiredness.

Source:

National Diabetes Information Clearinghouse: Diabetes Overview

Online Diabetes Symptoms: Diabetes and Fatigue

YGOY: What is Diabetes Disease and Fatigue All About?

More Information:

American Diabetes Association: Oral Medication

Your Total Health: Fatigue & Diabetes