The information listed below is not intended to replace professional consultation with your physician, to discuss your specific symptoms.
Common symptoms of both major types of diabetes (Type 1&2) include:
In diabetes, the body is inefficient and sometimes unable to use glucose for fuel. The body switches over to metabolizing fat, partially or completely, as a fuel source. This process requires the body to use more energy. The end result is feeling fatigued or constantly tired.
Unexplained weight loss
People with diabetes are unable to process many of the calories in the foods they eat. Thus, they may lose weight even though they eat an apparently appropriate or even excessive amount of food. Losing sugar and water in the urine and the accompanying dehydration also contributes to weight loss.
Excessive thirst (Polydipsia)
A person with diabetes develops high blood sugar levels, which overwhelms the kidney's ability to reabsorb the sugar as the blood is filtered to make urine. Excessive urine is made as the kidney spills the excess sugar. The body tries to counteract this by sending a signal to the brain to dilute the blood, which translates into thirst. The body encourages more water consumption to dilute the high blood sugar back to normal levels and to compensate for the water lost by excessive urination.
Excessive urination (Polyuria)
Another way the body tries to get rid of the extra sugar in the blood is to excrete it in the urine. This can also lead to dehydration because excreting the sugar carries a large amount of water out of the body along with it.
Excessive eating (Polyphagia)
If the body is able, it will secrete more insulin in order to try to deal with the excessive blood sugar levels. Moreover, the body is resistant to the action of insulin in type 2 diabetes. In uncontrolled diabetes where blood glucose levels remain abnormally high, glucose from the blood cannot enter the cells - due to either a lack of insulin or insulin resistance - so the body can’t convert the food into energy. This lack of energy causes an increase in hunger.
Poor wound healing
High blood sugar levels prevent white blood cells, which are important in defending the body against bacteria and also in cleaning up dead tissue and cells, from functioning normally. When these cells do not function properly, wounds take much longer to heal and become infected more frequently. Also, long-standing diabetes is associated with thickening of blood vessels, which prevents good circulation including the delivery of enough oxygen and other nutrients to body tissues.
Certain infection syndromes, such as frequent yeast infections of the genitals, skin infections, and frequent urinary tract infections, may result from suppression of the immune system by diabetes and by the presence of glucose in the tissues, which allows bacteria to grow well. They can also be an indicator of poor blood sugar control in a person known to have diabetes.
Altered mental status
Agitation, unexplained irritability, inattention, extreme lethargy, or confusion can all be signs of very high blood sugar, ketoacidosis, hyperosmolar hyperglycemia nonketotic syndrome, or hypoglycemia (low sugar). Thus, any of these merits needs immediate attention of a doctor.
Blurry vision is not specific for diabetes but is frequently present with high blood sugar levels.
Numbness or reduced ability to feel pain or changes in temperature, especially in feet and toes; Tingling or burning feeling, Pain when walking, Sharp pain that may be worse at night, Muscle weakness and difficulty walking, Slow stomach emptying leading to nausea, vomiting and loss of appetite, Difficulty swallowing, Erectile dysfunction in men, Vaginal dryness and other sexual difficulties in women, Increased or decreased sweating.
Standards of Medical Care in Diabetes2015. DIABETES Care 2015;3 (Suppl. 1)
Harrison’s Principles of Internal Medicine, edition 18, chapters 35, 94, 218, 21, 344
ISPAD Clinical Practice Consensus Guidelines 2014
Uptodate: Overview of medical care in adults with diabetes mellitus Author David K McCulloch, MD, Mar 18-2015
Uptodate: Glycemic control and vascular complication in type 2 diabetes mellitus, Author David K McCulloch, MD, Jun 2015