Semalam check tekanan darah... serius memang rendah giler... 70 lebih atas, 40 lebih bawah... bangun dari tido gelap mate..nampak bintik2 hitam...pastu takleh nak balance badan.. huyung hayang.. actually kite mmg dari dulu lagi low blood.. tak pernah normal.. ekekek...
so, today, we are going to learn...
what is 'Low Blood Pressure'Blood pressure is the pressure of blood within the arteries of the body. Blood pressure is the driving force that causes blood to flow through the body from the arteries (where the pressure is high), through organs, and into the veins (where the pressure is low). Blood pressure is generated by the pumping of blood by the heart into the arteries as well as by the resistance to the flow of blood by the arteries. The systolic blood pressure (the top number) represents the pressure in the arteries as the muscle of the heart contracts and pumps blood into the arteries. The diastolic blood pressure (the bottom number) represents the pressure in the arteries as the muscle of the heart relaxes after it contracts.
Systolic blood pressure for most healthy adults falls between 90 and 120 millimeters of mercury (mm Hg). Normal diastolic blood pressure falls between 60 and 80 mm Hg. (By convention, an individual’s blood pressure is written as systolic/diastolic blood pressure, e.g., 120/80). Current guidelines define normal blood pressure as lower than 120/80. Blood pressures between 120/80 and 140/90, which used to be considered “pre-hypertension,” now are considered too high. High blood pressure increases the risk of developing heart disease, kidney disease, hardening of the arteries (atherosclerosis or arteriosclerosis), eye damage, and stroke.
Low blood pressure is blood pressure that is so low that it is causing symptoms or signs due to the low flow of blood through the arteries and veins. When the flow of blood is too low to deliver enough oxygen and nutrients to vital organs such as the brain, heart, and kidney; the organs do not function normally and may be permanently damaged. It should be noted that unlike high blood pressure, which is defined on the basis of blood pressure alone, low blood pressure is defined primarily by signs and symptoms of low blood flow. In fact, some individuals may have a blood pressure of 90/50 and have no signs or symptoms of low blood pressure, and, therefore, not have low blood pressure while others who normally have a blood pressure of 130/80 may develop symptoms and signs of low blood pressure if their blood pressure drops to 100/60.
Is low blood pressure bad for your health?People who have lower blood pressures have a lower risk of strokes, kidney disease, and heart diseases. Athletes, people who exercise regularly, people who maintain ideal body weights, and non-smokers, tend to have lower blood pressures. Therefore, low blood pressure is desirable as long as it is not low enough to cause symptoms and damage to organs in the body.
What are low blood pressure signs and symptoms?When the blood pressure is not sufficient to deliver enough blood to the organs of the body, the organs do not work properly and may be permanently damaged. For example, if insufficient blood flows to the brain, brain cells do not receive enough oxygen and nutrients, and a person can feel light-headed, dizzy, or even faint. Going from a sitting or lying position to a standing position often brings out the symptoms of low blood pressure. This occurs because standing causes blood to “settle” in the veins of the lower body, and this can lower the blood pressure. If the blood pressure is already low, standing can make the low pressure worse to the point of causing symptoms. (The development of light-headedness, dizziness, or fainting upon standing caused by low blood pressure is called orthostatic hypotension. Normal individuals are able to compensate rapidly for the low pressure created by standing with the responses discussed previously and do not develop orthostatic hypotension.)
When there is insufficient blood pressure to deliver blood to the coronary arteries (the arteries that supply blood to the heart’s muscle), a person can develop chest pain (angina) or even a heart attack. When insufficient blood is delivered to the kidneys, the kidneys fail to eliminate wastes from the body, for example, urea and creatinine, and an increase in their levels in the blood occur (e.g., elevations of blood urea nitrogen or BUN and serum creatinine, respectively).
Shock is a life-threatening condition where persistently low blood pressure causes organs such as kidney, liver, heart, lung, and brain to fail rapidly.
What are the causes of low blood pressure?Conditions that reduce the volume of blood, reduce cardiac output (the amount of blood pumped by the heart), and medications are frequent causes of low blood pressure.
Causes of low blood pressure due to low blood volume * Dehydration is common among patients with diarrhea who lose large amounts of water in their stool, particularly when drowsiness limits their drinking of fluids or is associated with nausea and vomiting. Dehydration also can occur with prolonged vomiting of any cause because of the loss of water in the vomitus. Other causes of dehydration include exercise, sweating, fever, and heat exhaustion or heat stroke. Individuals with mild dehydration may experience only thirst and dry mouth. Moderate to severe dehydration may cause orthostatic hypotension (manifest by light-headedness, dizziness or fainting upon standing). Protracted and severe dehydration can lead to shock, kidney failure, confusion, acidosis (too much acid in the blood), coma, and even death. For more, please read the Dehydration article.
* Moderate or severe bleeding can quickly deplete an individual’s body of blood, leading to low blood pressure or orthostatic hypotension. Bleeding can result from trauma, surgical complications, or from gastrointestinal abnormalities such as ulcers, tumors, or diverticulosis. Occasionally, the bleeding may be so severe and rapid (for example, bleeding from a ruptured aortic aneurysm) that it causes shock rapidly.
* Severe inflammation of organs inside the body such as acute pancreatitis can cause low blood pressure. In acute pancreatitis, fluid leaves the blood to enter the inflamed tissues around the pancreas as well as the abdominal cavity, depleting the volume of blood.
Causes of low blood pressure due to heart disease
* Weakened heart muscle can cause the heart to fail and reduce the amount of blood it pumps. One common cause of weakened heart muscle is the death of a large portion of the heart’s muscle due to a single, large heart attack or repeated smaller heart attacks (please read the Heart Attack article for more). Other examples of conditions that can weaken the heart include medications that are toxic to the heart, infections of the muscle of the heart by viruses (myocarditis), and diseases of the heart’s valves such as aortic stenosis.
* Pericarditis is an inflammation of the pericardium (the sac surrounding the heart). Pericarditis can cause fluid to accumulate within the pericardium and around the heart, restricting the ability of the heart to pump blood.
* Pulmonary embolism is a condition in which a blood clot in a vein (a condition called deep vein thrombosis) breaks off and travels to the heart and eventually the lung. A large blood clot can block the flow of blood into the left ventricle from the lungs and severely diminish the ability of the heart to pump blood. Pulmonary embolism is a life-threatening emergency. For more, please read the Deep Vein Thrombosis and Pulmonary Embolism article.
* A slow heart rate (bradycardia) can decrease the amount of blood pumped by the heart. The resting heart rate for a healthy adult is between 60 and 100 beats/minute. Bradycardia (resting heart rates slower than 60 beats/minute) does not always cause low blood pressure. In fact, some highly trained athletes can have resting heart rates in the 40’s and 50’s without any symptoms. (The slow heart rates are offset by more forceful contractions of the heart that pump more blood than in non-athletes.) But in many patients bradycardia can lead to low blood pressure, light-headedness, dizziness, and even fainting.
One example of bradycardia, sick sinus syndrome, occurs common in the elderly. This syndrome is due to degeneration of the sinus node (SA node), an area in the heart that generates electrical signals that cause the heart to beat regularly. In the sick sinus syndrome, the diseased SA node cannot generate signals fast enough to maintain a normal heart rate. Another condition that causes bradycardia is heart block. Electrical signals from the SA node must travel to the rest of the heart’s muscle to cause the heart to contract and pump blood. Normally these electrical signals are transmitted along special tissues in the heart. Heart block occurs when these specialized tissues are damaged by heart attacks, degeneration that occurs with aging, and medications. Heart block prevents some or all of the electrical signals generated by the SA node from reaching the rest of the heart, and this prevents the heart from contracting as rapidly as it otherwise would.
* An abnormally fast heart rate (tachycardia) also can cause low blood pressure. The most common example of tachycardia causing low blood pressure is atrial fibrillation. Atrial fibrillation is a disorder of the heart characterized by rapid and irregular electrical discharges from the muscle of the heart (instead of the SA node), causing the ventricles to contract irregularly and (usually) rapidly. The rapidly contracting ventricles do not have enough time to fill maximally with blood before the each contraction, and the amount of blood that is pumped decreases, in spite of the faster heart rate. Other abnormally rapid heart rhythms such as ventricular tachycardia also can produce low blood pressure, sometimes even life-threatening shock. For more, please read the Atrial Fibrillation article.
Medications that cause low blood pressure * Medications such as calcium channel blockers, beta blockers, and digoxin (Lanoxin) can slow the rate at which the heart contracts. Some elderly people are extremely sensitive to these medications since they are more likely to have diseased SA nodes and electrical conduction tissues. In some individuals, the heart rate can become dangerously slow even with small doses of these medications.
* Medications used in treating high blood pressure (such as ACE inhibitors, angiotensin receptor blockers, beta-blockers, calcium channel blockers, and alpha-blockers) can excessively lower blood pressure and result in symptomatic low blood pressure especially among the elderly.
* Diuretics (water pills) such as furosemide (Lasix) can decrease blood volume by causing excessive urination.
* Medications used for treating depression, such as amitriptyline (Elavil), Parkinson’s disease, such as levodopa-carbidopa (Sinemet), erectile dysfunction (impotence), such as sildenafil (Viagra) when used in combination with nitroglycerine, can cause low blood pressure
* Alcohol and narcotics also can cause low blood pressure.
Other condition s that cause low blood pressure * Vasovagal reaction is a common condition in which a healthy person temporarily develops low blood pressure, slow heart rate, and sometimes fainting. A vasovagal reaction typically is brought on by emotions of fear or pain such as having blood drawn or starting an intravenous infusion. Vasovagal reactions are caused by the involuntary (autonomic) nervous system releasing hormones that slow the heart and widen the blood vessels.
* Postural (orthostatic) hypotension, as discussed previously, is a sudden drop in blood pressure when an individual stands up from a sitting, squatting, or supine (lying) position. When a person stands up, gravity causes blood to settle in the veins in the legs, hence less blood reaches the heart for pumping, and, as a result, the blood pressure drops. The body normally responds automatically to the drop in blood pressure by increasing the rate at which the heart beats and by narrowing the veins to return more blood to the heart. In patients with postural hypotension, this compensating reflex fails to occur, resulting in symptomatic low blood pressure. Postural hypotension can occur in persons of all ages but is much more common among the elderly, especially in those on medications for high blood pressure and/or diuretics. Other causes of postural hypotension include dehydration, adrenal insufficiency (discussed shortly), prolonged bed rest, diabetes that has caused damage to the autonomic nerves, alcoholism with damage to the autonomic nerves, and certain rare neurological syndromes (e.g., Shy-Drager syndrome) that damage the autonomic nerves.
* Another form of postural hypotension occurs typically in young healthy individuals. After prolonged standing, the individual’s heart rate and blood pressure drops, causing dizziness, nausea and often fainting. In these individuals, the autonomic nervous system wrongly responds to prolonged standing by directing the heart to slow down and the veins to dilate.
* Micturition syncope is a temporary drop in blood pressure and loss of consciousness brought about by urinating. This condition typically occurs in elderly patients and may be due to the release by the autonomic nerves of hormones that lower blood pressure.
* Adrenal insufficiency, for example, due to Addison’s disease, can cause low blood pressure. Addison’s disease is a disorder in which the adrenal glands (small glands next to the kidneys) are destroyed. The destroyed adrenal glands can no longer produce sufficient adrenal hormones (specifically cortisol) necessary for to maintain normal bodily functions. Cortisol has many functions, one of which is to maintain blood pressure and the function of the heart. Addison’s disease is characterized by loss of weight, muscle weakness, fatigue, low blood pressure, and, sometimes, darkening of the skin.
* Septicemia is a severe infection in which bacteria (or other infectious organisms such as fungi) enter the blood. The infection typically originates in the lungs (as pneumonia), bladder, or in the abdomen due to diverticulitis or gallstones. The bacteria then enter the blood where they release toxins and cause life-threatening and profound low blood pressure (septic shock), often with damage to several organs.
* Anaphylaxis (anaphylactic shock) is a potentially fatal allergic reaction to medications such as penicillin, intravenous iodine used in some x-ray studies, foods such as peanuts, or bee stings. In addition to a profound drop in blood pressure, individuals may also experience hives, wheezing, and a swollen throat with difficulty breathing.
How is low blood pressure diagnosed and evaluated?In some individuals, particularly relatively healthy ones, symptoms of weakness, dizziness, and fainting raise the suspicion of low blood pressure. In others, an event often associated with low blood pressure, for example, a heart attack, has occurred to cause the symptoms. Measuring blood pressure, sometimes in both the lying (supine) and standing positions usually is the first step in diagnosing low blood pressure. In patients with symptomatic low blood pressure, there often is a marked drop in blood pressure upon standing, and patients may even develop orthostatic symptoms. Once low blood pressure has been identified as the cause of symptoms, the goal is to identify the cause of the low blood pressure. Sometimes the causes are readily apparent (such as loss of blood due to trauma, or sudden shock after receiving x-ray dyes containing iodine). At other times, the cause may be identified by testing:
* CBC (complete blood count). CBC may reveal anemia from blood loss or elevated white blood cells due to infection.
* Blood electrolyte measurements may show dehydration and mineral depletion, renal failure, or acidosis (excess acid in the blood).
* Cortisol levels can be measured to diagnose adrenal insufficiency and Addison’s disease.
* Blood and urine cultures can be performed to diagnose septicemia and bladder infections, respectively.
* Radiology studies, such as chest x-rays, abdominal ultrasounds and computerized tomography (CT or CAT) scans may detect pneumonia, heart failure, gallstones, pancreatitis, and diverticulitis.
* Electrocardiograms (EKG) can detect abnormally slow or rapid heart beats, pericarditis, and heart muscle damage from either old heart attacks or a reduced supply of blood to the heart muscle that has not yet caused a heart attack.
* Holter monitor recordings are used to diagnose intermittent episodes of abnormal heart rhythms. If abnormal rhythms occur intermittently, a standard EKG performed at the time of a visit to the doctor's office may not show the abnormal rhythm. A Holter monitor is a continuous recording of the heart's rhythm for 24 hours that often is used to diagnose intermittent episodes of bradycardia or tachycardia.
* Patient-activated event recorder. If the episodes of bradycardia or tachycardia are infrequent, a 24-hour Holter recording may not capture these sporadic episodes. In this situation, a patient can wear a patient-activated event recorder for up to four weeks. The patient presses a button to start the recording when he or she senses the onset of an abnormal heart rhythm or symptoms possibly caused by hypotension. The doctor then analyzes the recordings at a later date to identify the abnormal episodes.
* Echocardiograms are examinations of the structures and motion of the heart using ultrasound. Echocardiograms can detect pericardial fluid due to pericarditis, the extent of heart muscle damage from heart attacks, diseases of the heart valves, and rare tumors of the heart.
* Ultrasound examinations of the leg veins and CT scans of the chest can detect deep vein thrombosis and pulmonary embolism.
* Tilt-table tests are used to evaluate patients suspected of having postural hypotension or syncope due to abnormal autonomic nerves. During a tilt-table test, the patient lies on an examining table with an intravenous infusion running while the heart rate and blood pressure are monitored. The table then is tilted upright for 15 minutes to 45 minutes. Heart rate and blood pressure are monitored every few minutes. The purpose of the test is to try to reproduce postural hypotension. Sometimes a doctor may administer Isuprel intravenously to induce postural hypotension. For more, please read our Tilt-table Test procedure article.
How is low blood pressure treated?Low blood pressure in healthy subjects without symptoms or organ damage needs no treatment. All patients with symptoms possibly due to low blood pressure should be evaluated by a doctor. (Patients who have had a major drop in blood pressure from their usual levels even without the development of symptoms also should be evaluated.) The doctor needs to identify the cause of the low blood pressure since treatment will depend on the cause. For example, if a medication is causing the low blood pressure, the dose of medication may have to be reduced or the medication stopped, though only after consulting the doctor. Self-adjustment of medication should not be done.
* Dehydration is treated with fluids and minerals (electrolytes). Mild dehydration without nausea and vomiting can be treated with oral fluids and electrolytes. Moderate to severe dehydration usually is treated in the hospital or emergency room with intravenous fluids and electrolytes.
* Blood loss can be treated with intravenous fluids and blood transfusions. If bleeding is continuing, it needs to be treated as well.
* Septicemia is treated with intravenous fluids and antibiotics.
* Blood pressure medications or diuretics are adjusted, changed, or stopped by the doctor if they are causing low blood pressure symptoms.
* Bradycardia may be due to a medication. The doctor may reduce, change or stop the medication. Bradycardia due to sick sinus syndrome or heart block is treated with an implantable pacemaker.
* Tachycardia is treated depending on the nature of the tachycardia. Atrial fibrillation can be treated with oral medications, electrical cardioversion, or a catheterization procedure called pulmonary vein isolation. Ventricular tachycardia can be controlled with medications or with an implantable defibrillator.
* Pulmonary embolism and deep vein thrombosis is treated with blood thinners, intravenous heparin initially and oral warfarin later.
* Pericardial fluid can be removed by a procedure called pericardiocentesis.
* Postural hypotension can be treated by increasing water and salt intake, using compression stockings to compress the leg veins and reduce the pooling of blood in the veins, and, in some patients, the use of a medication called proamatine (Midodrine). The problem with proamatine is that while it increases blood pressure in the upright position, the supine blood pressure may become too high, thus increasing the risk of strokes. Mayo clinic researchers found that a medication used to treat muscle weakness in Myasthenia gravis called pyridostigmine (Mestinon) increases upright blood pressure but not supine blood pressure. Mestinon is an anticholinesterase medication that works on the autonomic nervous system, especially when a person is standing up. Side effects of pyridostigmine include minor abdominal cramping or increased frequency of bowel movements. Increasing salt intake can lead to heart failure in patients with existing heart disease and should not be undertaken without consulting a doctor.
actually, kite dah banyak kali gak ah pi klinik risau ngn tekanan darah ni.. memang rendah, but doktor cakap it is normal bagi orang yg kurus.. tapi tak leh lah rendah sgt.. therefore... for my case darah yg agak rendah sgt2 nie... the same advice i got from my doctor which is... exercise! hari2 bersenam! So he gave me some suggestions such as jogging.. playing netball.. or badminton...
Jadi... JOM BERSENAM!!!
