Renovascular hypertension (RVHT) causes 0.2-4% of cases. Since the seminal experiment in 1934 by Goldblatt et al,  RVHT has become increasingly recognized as an important cause of clinically atypical hypertension and chronic kidney disease—the latter by virtue of renal ischemia. The coexistence of renal arterial vascular (ie, renovascular) disease and hypertension roughly defines this type of nonessential hypertension. More specific diagnoses are made retrospectively when hypertension is improved after intravascular intervention.
Metabolic syndrome promotes coronary heart disease through several mechanisms. It increases the thrombogenicity of circulating blood, in part by raising plasminogen activator type 1 and adipokine levels, and it causes endothelial dysfunction.  Metabolic syndrome may also increase cardiovascular risks by increasing arterial stiffness.  Additional mechanisms include oxidative stress,  which has been associated with numerous components of metabolic syndrome. 
“Too often, doctors don’t set reasonable expectations,” says Lauren Harris-Pincus, RDN, of New York City. A blanket statement like "'Lose weight and go exercise' is not as motivating as 'If you lose a modest 5 percent of your body weight, you can make a significant impact on the important numbers like blood pressure, blood sugar, and cholesterol/triglycerides,'” Harris-Pincus says.
Cortisol reactivity, an index of hypothalamic-pituitary-adrenal function, may be another mechanism by which psychosocial stress is associated with future hypertension.  In a prospective sub-study of the Whitehall II cohort, with 3 years follow-up of an occupational cohort in previously healthy patients, investigators reported 15.9% of the patient sample developed hypertension in response to laboratory-induced mental stressors and found an association between cortisol stress reactivity and incident hypertension. 
Cataracts and glaucoma are also more common among diabetics. It is also important to note that since the lens of the eye lets water through, if blood sugar concentrations vary a lot, the lens of the eye will shrink and swell with fluid accordingly. As a result, blurry vision is very common in poorly controlled diabetes. Patients are usually discouraged from getting a new eyeglass prescription until their blood sugar is controlled. This allows for a more accurate assessment of what kind of glasses prescription is required.