Diabetes mellitus (DM) is a metabolic disease characterized by increased levels of sugar in the blood, also known as hyperglycemia. Two variants of DM exist: type 1 diabetes mellitus and type 2 diabetes mellitus. Type 1 is characterized by an autoimmune nature, with the production of antibodies against cell in the pancreas that secrete a hormone known as insulin. Insulin is a major regulator of the levels of sugar in the blood, and its deficiency results in the syndrome of diabetes. Type 1 DM typically presents in younger patients and responds only to exogenous insulin production.
Excessive Thirst and Appetite
Diabetics have increased amount of thirst (known as polydipsia) and hunger (known as polyphagia) due to a variety of different reasons, according to the Williams Textbook of Endocrinology. The body tries to excrete the sugar in the urine, and the sugar molecules "pull" water out of the body with it. This results in loss of bodily fluid and thirst is a compensatory reaction in an attempt to refill lost fluid stores. Insulin also works to "push" sugar and nutrients into body cells, and its deficiency results in nutrient-deprived body cells. As a result, the body tries to eat more food in an attempt to nourish itself, resulting in constant hunger.
Fatigue
Diabetic patients also commonly suffer from fatigue and lethargy, states the Mayo Clinic. This can be due to loss of fluids and electrolytes in the urine from the increased amount of sugar in the urine. This can also be a result of the insulin deficiency, which results in decreased nutrition being delivered to cells of the body.
Visual Disturbances
Increased levels of blood sugar cause damage to blood vessels, especially in the eye. This is known as diabetic retinopathy. On ophthalmologic exam, the patient can be seen to have hemorrhages, exudates and even detachment of the retina. This can result in blurry and/or decreased vision, and even eventual blindness.
Neuropathy
This refers to nerve damage as a result of the increased blood sugar levels. The increased sugar can be absorbed into the sheaths that surround nerves and "pull" fluid in with them. As a result of the subsequent swelling, nerve damage ensues. Symptoms include tingling, numbness, weakness, pain, impotence, urinary disruption (such as urine retention and incontinence), diarrhea and constipation, according to the Williams Textbook of Endocrinology .
Nausea and Vomiting
Diabetics suffer from nausea and vomiting from a variety of different reasons, explains the Step-Up to Medicine textbook. The fluid and electrolyte disturbances that occur with diabetes can be a major factor. In addition, the stomach retains food contents longer than expected due to nerve damage. This buildup of food and stomach juices can result in chronic nausea and vomiting. Diabetes also damages the kidneys, which are responsible for excretion of various waste products in the blood. Decreased kidney function results in buildup of waste products, which can also predispose the patient to nausea and vomiting.
Diabetic Foot
The feet are affected in many ways by diabetes. Increased blood sugar not only damages the nerves but can also damage the blood vessels in the body, especially ones that supply extremities like the foot. As a result of the nerve damage, the patient can inadvertently damage his foot without feeling the associated pain. The wound also has impaired healing due not only to decreased blood flow from damaged arteries but to the detrimental effects of blood sugar on white blood cells that usually fight infection. As a result, chronic ulcers can result, which can ultimately lead to infection of the soft tissues and bone. Once this occurs, amputation becomes likely.
References
- "Williams Textbook of Endocrinology, 11th Edition"; Kronenberg; 2008
- "Step-Up to Medicine, 2nd Edition"; Agabegi; 2008
