Several other signs and symptoms can mark the onset of diabetes although they are not specific to the disease. In addition to the known ones above, they include blurred vision, headache, fatigue, slow healing of cuts, and itchy skin. Prolonged high blood glucose can cause glucose absorption in the lens of the eye, which leads to changes in its shape, resulting in vision changes. Long-term vision loss can also be caused by diabetic retinopathy. A number of skin rashes that can occur in diabetes are collectively known as diabetic dermadromes.
James, Paul A.; Oparil, Suzanne; Carter, Barry L.; Cushman, William C.; Dennison-Himmelfarb, Cheryl; Handler, Joel; Lackland, Daniel T.; Lefevre, Michael L.; MacKenzie, Thomas D.; Ogedegbe, Olugbenga; Smith, Sidney C.; Svetkey, Laura P.; Taler, Sandra J.; Townsend, Raymond R.; Wright, Jackson T.; Narva, Andrew S.; Ortiz, Eduardo (18 December 2013). "2014 Evidence-Based Guideline for the Management of High Blood Pressure in Adults". JAMA. 311 (5): 507–20. doi:10.1001/jama.2013.284427. PMID 24352797.
According to the Mayo Clinic, doctors may use other tests to diagnose diabetes. For example, they may conduct a fasting blood glucose test, which is a blood glucose test done after a night of fasting. While a fasting blood sugar level of less than 100 milligrams per deciliter (mg/dL) is normal, one that is between 100 to 125 mg/dL signals prediabetes, and a reading that reaches 126 mg/dL on two separate occasions means you have diabetes.