Diuretics can lead to an increase in potassium loss, known as hypokalemia, which, in turn can affect muscular function -- including the muscles of the heart. There is also an increased risk for gout with diuretics -- as well as the possibility of weakness, thirst, dehydration, and increased urination. Changes in blood sugar levels are also possible. Skin reactions, some severe, are possible with thiazide diuretics (such as hydrochlorothiazide). Potassium-sparing diuretics, such as spironolactone (Aldactone) may cause breast enlargement in males.
Medicines are available if these changes do not help control your blood pressure within 3 to 6 months. Diuretics help rid your body of water and sodium. ACE inhibitors block the enzyme that raises your blood pressure. Other types of medicines— beta blockers, calcium channel blockers, and other vasodilators—work in different ways, but their overall effect is to help relax and widen your blood vessels and reduce the pressure inside the vessel. [See also the free government publication “Medicines to Help You: High Blood Pressure” (PDF) from the US Food and Drug Administration.]
As blood travels throughout your body, it presses against the walls of your blood vessels, just like water in a hose or air in a tire. This is called blood pressure. When your heart beats (contracts), squeezing blood out and pumping it into your arteries, blood pressure peaks. This is called your systolic pressure. Between heartbeats, when your heart relaxes and blood flows back into it, your blood pressure is lower. This is your diastolic pressure.
Many expert groups recommend a slightly higher target of 150/90 mmHg for those over somewhere between 60 and 80 years of age.[99][100][101][105] The JNC-8 and American College of Physicians recommend the target of 150/90 mmHg for those over 60 years of age,[13][106] but some experts within these groups disagree with this recommendation.[107] Some expert groups have also recommended slightly lower targets in those with diabetes[99] or chronic kidney disease with protein loss in the urine,[108] but others recommend the same target as for the general population.[13][103] The issue of what is the best target and whether targets should differ for high risk individuals is unresolved,[109] although some experts propose more intensive blood pressure lowering than advocated in some guidelines.[110]

At the most basic level, hypotension can cause dizziness or blurry vision, which may increase the risk of falling or contribute to accidents. In more serious cases, it reduces the blood flow to the brain and other vital organs. This decreases the amount of oxygen and nutrients being delivered to these organs and impairs their ability to carry out normal functions. Hypotension may also indicate a more serious underlying health condition.
A desired blood pressure is less than 120/80. In people who are considered to be healthy, low blood pressure without experiencing any symptoms is commonly not a concern and does not need to be treated. Low blood pressure may be a sign of an underlying issue, particularly in seniors, where it might cause inadequate blood floor to their heart, vital organs, and brain.
^ Ostchega Y, Dillon CF, Hughes JP, Carroll M, Yoon S (July 2007). "Trends in hypertension prevalence, awareness, treatment, and control in older U.S. adults: data from the National Health and Nutrition Examination Survey 1988 to 2004". Journal of the American Geriatrics Society. 55 (7): 1056–65. doi:10.1111/j.1532-5415.2007.01215.x. PMID 17608879.
Secondary hypertension results from an identifiable cause. Kidney disease is the most common secondary cause of hypertension.[23] Hypertension can also be caused by endocrine conditions, such as Cushing's syndrome, hyperthyroidism, hypothyroidism, acromegaly, Conn's syndrome or hyperaldosteronism, renal artery stenosis (from atherosclerosis or fibromuscular dysplasia), hyperparathyroidism, and pheochromocytoma.[23][47] Other causes of secondary hypertension include obesity, sleep apnea, pregnancy, coarctation of the aorta, excessive eating of liquorice, excessive drinking of alcohol, and certain prescription medicines, herbal remedies, and illegal drugs such as cocaine and methamphetamine.[23][48] Arsenic exposure through drinking water has been shown to correlate with elevated blood pressure.[49][50]
Do not attempt to lower extremely elevated blood pressure in yourself or someone else. While the goal is to reduce blood pressure before additional complications develop, blood pressure should be reduced over the course of hours to days, depending on severity. It is important not to lower blood pressure too quickly, because rapid blood pressure reductions can cut off the supply of blood to the brain, leading to brain damage or death.
If your blood pressure is above the normal range for up to 5 readings (taken at different visits), your doctor will likely diagnose you with high blood pressure. Sometimes the doctor may diagnose you after a fewer number of readings, depending on how high above normal your blood pressure is and if you have other medical conditions. Blood pressure tends to be at its highest during exercise, physical work, or stress, and lowest during sleep. Everyone can have a temporary increase in blood pressure at one time or another, which is why it's important to take multiple readings.
Your doctor can help you measure and track your blood pressure to confirm whether it’s too high. You may need to start taking medications if your blood pressure doesn’t improve after one month of following a healthy lifestyle, especially if you’re already at high risk for heart disease. If you’re at lower risk, your doctor may want to follow up in three to six months after you’ve adopted more healthy habits.

High blood pressure, or hypertension, is a condition in which the force of blood against artery walls is too strong. It is common ailment, and it is common for many Veterans to hear about hypertension at their health care appointments. Over time, without treatment, high blood pressure can damage the arteries, heart, and kidneys and can lead to heart disease and stroke.
In the 19th and 20th centuries, before effective pharmacological treatment for hypertension became possible, three treatment modalities were used, all with numerous side-effects: strict sodium restriction (for example the rice diet[152]), sympathectomy (surgical ablation of parts of the sympathetic nervous system), and pyrogen therapy (injection of substances that caused a fever, indirectly reducing blood pressure).[152][158]
High blood pressure is a common disease in which blood flows through blood vessels, or arteries, at higher than normal pressures. Blood pressure is the force of blood pushing against the walls of your arteries as the heart pumps blood. High blood pressure, sometimes called hypertension, is when this force against the artery walls is too high. Your doctor may diagnose you with high blood pressure if you have consistently high blood pressure readings.
With low blood pressure, the patient may feel faint or lose consciousness. This is due to lack of blood flow to the brain, and usually laying the patient supine will help them come round. This is also known as a blackout, and it could be accompanied by a dizzy feeling and light-headedness. Generally, your patient will report trouble focusing, difficulty keeping upright and lack of coordination.