Many expert groups recommend a slightly higher target of 150/90 mmHg for those over somewhere between 60 and 80 years of age. The JNC-8 and American College of Physicians recommend the target of 150/90 mmHg for those over 60 years of age, but some experts within these groups disagree with this recommendation. Some expert groups have also recommended slightly lower targets in those with diabetes or chronic kidney disease with protein loss in the urine, but others recommend the same target as for the general population. The issue of what is the best target and whether targets should differ for high risk individuals is unresolved, although some experts propose more intensive blood pressure lowering than advocated in some guidelines.
Defining abnormally high blood pressure (BP) is extremely difficult and arbitrary. Furthermore, the relationship between systemic arterial pressure and morbidity appears to be quantitative rather than qualitative. A level for high BP must be agreed upon in clinical practice for screening patients with hypertension and for instituting diagnostic evaluation and initiating therapy. Because the risk to an individual patient may correlate with the severity of hypertension, a classification system is essential for making decisions about aggressiveness of treatment or therapeutic interventions. (See Presentation.)
In the Framingham Heart Study, the age-adjusted risk of congestive heart failure was 2.3 times higher in men and 3 times higher in women when the highest BP was compared to the lowest BP.  Multiple Risk Factor Intervention Trial (MRFIT) data showed that the relative risk for coronary artery disease mortality was 2.3 to 6.9 times higher for persons with mild to severe hypertension than it was for persons with normal BP.  The relative risk for stroke ranged from 3.6 to 19.2. The population-attributable risk percentage for coronary artery disease varied from 2.3 to 25.6%, whereas the population-attributable risk for stroke ranged from 6.8-40%. https://i.ytimg.com/vi/54Ep_LFJ9Wc/3.jpg
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.
Globally, an estimated 26% of the world’s population (972 million people) has hypertension, and the prevalence is expected to increase to 29% by 2025, driven largely by increases in economically developing nations.  The high prevalence of hypertension exacts a tremendous public health burden. As a primary contributor to heart disease and stroke, the first and third leading causes of death worldwide, respectively, high blood pressure was the top modifiable risk factor for disability adjusted life-years lost worldwide in 2013. [35, 36]
The pressure generated by the beating heart forces the blood forward and stretches the elastic walls of the arteries. In between heartbeats, as the heart muscle relaxes, the arterial walls snap back to their original shape, moving the blood forward to the body’s tissues. With hypertension, the pressure in the arteries is high enough to eventually produce damage to the blood vessels.
Insulin is vital to patients with type 1 diabetes - they cannot live without a source of exogenous insulin. Without insulin, patients with type 1 diabetes develop severely elevated blood sugar levels. This leads to increased urine glucose, which in turn leads to excessive loss of fluid and electrolytes in the urine. Lack of insulin also causes the inability to store fat and protein along with breakdown of existing fat and protein stores. This dysregulation, results in the process of ketosis and the release of ketones into the blood. Ketones turn the blood acidic, a condition called diabetic ketoacidosis (DKA). Symptoms of diabetic ketoacidosis include nausea, vomiting, and abdominal pain. Without prompt medical treatment, patients with diabetic ketoacidosis can rapidly go into shock, coma, and even death may result.