Enlarged heart. High blood pressure increases the amount of work for your heart. Like any heavily exercised muscle in your body, your heart grows bigger (enlarges) to handle the extra workload. The bigger your heart is, the more it demands oxygen-rich blood but the less able it is to maintain proper blood flow. As a result, you feel weak and tired and are not able to exercise or perform physical activities. Without treatment, your heart failure will only get worse.


The American Heart Association, or AHA, explains that the early symptoms of high blood pressure that people tend to think about are largely mythical. You are unlikely to notice “classic” signs such as anxiety, insomnia, or flushing in your face. You could have blood spots in your eyes due to subconjunctival hemorrhage, but dizziness itself is not among the essential symptoms of high blood pressure.
Metformin may be quantified in blood, plasma, or serum to monitor therapy, confirm a diagnosis of poisoning, or assist in a forensic death investigation. Blood or plasma metformin concentrations are usually in a range of 1–4 mg/l in persons receiving therapeutic doses, 40–120 mg/l in victims of acute overdosage, and 80–200 mg/l in fatalities. Chromatographic techniques are commonly employed.[86][87]
^ Jump up to: a b Shu AD, Myers MG, Shoelson SE (2005). "Chapter 29: Pharmacology of the Endocrine Pancreas". In Golan ED, Tashjian AH, Armstrong EJ, Galanter JM, Armstrong AW, Arnaout RA, Rose HS. Principles of pharmacology: the pathophysiologic basis of drug therapy. Philadelphia: Lippincott, Williams & Wilkins. pp. 540–41. ISBN 978-0-7817-4678-6.
The incidence of diabetes was 58% lower in the lifestyle group and 31% lower in individuals given metformin. Among younger people with a higher body mass index, lifestyle modification was no more effective than metformin, and for older individuals with a lower body mass index, metformin was no better than placebo in preventing diabetes.[35] After ten years, the incidence of diabetes was 34% lower in the group of participants given diet and exercise and 18% lower in those given metformin.[36] It is unclear whether metformin slowed down the progression of prediabetes to diabetes (true preventative effect), or the decrease of diabetes in the treated population was simply due to its glucose-lowering action (treatment effect).[37]
Recent updates to guidelines from the American Heart Association and the American College of Cardiology changed the definition of high blood pressure or hypertension for most people. High blood pressure is now generally defined as 130 or higher for the first number, or 80 or higher for the second number (previously it was 140/90). However, there are important considerations for older adults in deciding whether to start treatment for high blood pressure, including other health conditions and overall fitness. If your blood pressure is above 130/80, your doctor will evaluate your health to determine what treatment is needed to balance risks and benefits in your particular situation.
Start low and go slow. When starting metformin, most people do well with starting with 500 mg at night or with dinner, and staying at this dose for a full week. At that point, a second 500-mg pill can be added in the morning. After another week, a third pill can be added to the evening dose. After one more week, a fourth pill can be added to the morning dose, so that by the end of the month, the full daily dose of 2,000 mg is being taken.
On average, diabetics are found to produce two to three times more glucose in their liver than non-diabetics. Metformin effectively suppresses glucose production in the liver. Metformin also makes cells more sensitive to insulin. Experts agree that diabetes starts with insulin resistance. Insulin is the courier that carries glucose from your food into cells. When cells resist, insulin is not able to deliver sugar into muscle and fat cells. Sugar then backs up in the bloodstream instead.
Side effects such as diarrhea and gas are common when beginning the medication, but can often be alleviated by carefully titrating the dose upward over a period of time. Less common but possibly serious side effects may include lactic acidosis and B12 deficiency. Knowing the possible symptoms of lactic acidosis and monitoring B12 can offset most serious complications.
Aldosterone release: This steroid hormone is released from the adrenal cortex in response to angiotensin II or high serum potassium levels. Aldosterone stimulates sodium retention and potassium excretion by the kidneys. Since sodium is the main ion that determines the amount of fluid in the blood vessels by osmosis, aldosterone will increase fluid retention, and indirectly, arterial pressure.

Pulmonary hypertension is caused by changes in the cells that line the pulmonary arteries. These changes cause the walls of the arteries to become stiff and thick, extra tissue may also form. This can reduce or block blood flow through the blood vessels. Increased blood pressure is then caused because it is harder for blood to flow. Pulmonary hypertension can be an associated condition with scleroderma, sarcoidosis, pulmonary embolism, and dermatomyositis.

If you experience any of the following symptoms, stop taking metformin and call your doctor immediately: extreme tiredness, weakness, or discomfort; nausea; vomiting; stomach pain; decreased appetite; deep and rapid breathing or shortness of breath; dizziness; lightheadedness; fast or slow heartbeat; flushing of the skin; muscle pain; or feeling cold, especially in your hands or feet.


Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.Information last revised July 2018. Copyright(c) 2018 First Databank, Inc.
Metformin is cleared from the body by the kidneys, as are contrast dyes. When the two are combined, they carry a theoretical risk of kidney damage from overload. In addition, toxic levels of metformin can build up in the blood due to short-term reduced kidney function from the contrast dye, increasing the risk of lactic acidosis (an emergency situation in which the blood becomes acidic).
The guidelines, from the American Heart Association (AHA) and the American College of Cardiology (ACC), now define high blood pressure as 130 mm Hg or higher for the systolic blood pressure measurement, or 80 mm Hg or higher for the diastolic blood pressure measurement. (Systolic is the top number, and diastolic is the bottom number, in a blood pressure reading.) Previously, high blood pressure was defined as 140 mm Hg or higher for the systolic measurement and 90 or higher for the diastolic measurement.
×