^ Feinman, R. D; Pogozelski, W. K; Astrup, A; Bernstein, R. K; Fine, E. J; Westman, E. C; Accurso, A; Frassetto, L; Gower, B. A; McFarlane, S. I; Nielsen, J. V; Krarup, T; Saslow, L; Roth, K. S; Vernon, M. C; Volek, J. S; Wilshire, G. B; Dahlqvist, A; Sundberg, R; Childers, A; Morrison, K; Manninen, A. H; Dashti, H. M; Wood, R. J; Wortman, J; Worm, N (2015). "Dietary carbohydrate restriction as the first approach in diabetes management: Critical review and evidence base". Nutrition. 31 (1): 1–13. doi:10.1016/j.nut.2014.06.011. PMID 25287761.
Hypertension results from a complex interaction of genes and environmental factors. Numerous common genetic variants with small effects on blood pressure have been identified as well as some rare genetic variants with large effects on blood pressure. Also, genome-wide association studies (GWAS) have identified 35 genetic loci related to blood pressure; 12 of these genetic loci influencing blood pressure were newly found. Sentinel SNP for each new genetic locus identified has shown an association with DNA methylation at multiple nearby CpG sites. These sentinel SNP are located within genes related to vascular smooth muscle and renal function. DNA methylation might affect in some way linking common genetic variation to multiple phenotypes even though mechanisms underlying these associations are not understood. Single variant test performed in this study for the 35 sentinel SNP (known and new) showed that genetic variants singly or in aggregate contribute to risk of clinical phenotypes related to high blood pressure.
Historically the treatment for what was called the "hard pulse disease" consisted in reducing the quantity of blood by bloodletting or the application of leeches. This was advocated by The Yellow Emperor of China, Cornelius Celsus, Galen, and Hippocrates. The therapeutic approach for the treatment of hard pulse disease included changes in lifestyle (staying away from anger and sexual intercourse) and dietary program for patients (avoiding the consumption of wine, meat, and pastries, reducing the volume of food in a meal, maintaining a low-energy diet and the dietary usage of spinach and vinegar).
Metabolic syndrome is thought to be caused by adipose tissue dysfunction and insulin resistance. Dysfunctional adipose tissue also plays an important role in the pathogenesis of obesity-related insulin resistance.  Both adipose cell enlargement and infiltration of macrophages into adipose tissue result in the release of proinflammatory cytokines and promote insulin resistance. 
^ Qaseem A, Wilt TJ, Rich R, Humphrey LL, Frost J, Forciea MA (17 January 2017). "Pharmacologic Treatment of Hypertension in Adults Aged 60 Years or Older to Higher Versus Lower Blood Pressure Targets: A Clinical Practice Guideline From the American College of Physicians and the American Academy of Family Physicians". Annals of Internal Medicine. 166 (6): 430–437. doi:10.7326/M16-1785. PMID 28135725.
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. 
To treat diabetic retinopathy, a laser is used to destroy and prevent the recurrence of the development of these small aneurysms and brittle blood vessels. Approximately 50% of patients with diabetes will develop some degree of diabetic retinopathy after 10 years of diabetes, and 80% retinopathy after 15 years of the disease. Poor control of blood sugar and blood pressure further aggravates eye disease in diabetes.
Your doctor may have handed you an info sheet on the foods you should be avoiding, but you might make more progress by adding certain foods to your diet. Focus on incorporating foods rich in soluble fiber, like oats and beans, into your meals. Insoluble fibers like whole grains can provide a "moving experience" by transporting foods through your gastrointestinal tract while keeping you feeling satisfied. Fill at least half your plate with veggies and fruits, and choose whole-grain carbs to make less room on your plate (and in your stomach) for less-beneficial choices.
Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure typically does not cause symptoms. Long-term high blood pressure, however, is a major risk factor for coronary artery disease, stroke, heart failure, atrial fibrillation, peripheral vascular disease, vision loss, chronic kidney disease, and dementia.
Hypertension is rarely accompanied by symptoms, and its identification is usually through screening, or when seeking healthcare for an unrelated problem. Some people with high blood pressure report headaches (particularly at the back of the head and in the morning), as well as lightheadedness, vertigo, tinnitus (buzzing or hissing in the ears), altered vision or fainting episodes. These symptoms, however, might be related to associated anxiety rather than the high blood pressure itself.