Learn more about the causes, symptoms and treatment of low blood pressure, a condition in which your blood pressure reading is lower than. Low blood pressure is a reading of 90/60mmHg or less. It doesn't always cause symptoms, but you may need treatment if it does. The American Heart Association explains low blood pressure and how low is too low? Find out the symptoms of low blood pressure and the causes of low blood.
Pressure Low Blood
Skip the main banner if you do not want to read it as the next section. You can return to the page content navigation from here. Many people worry about low blood pressure hypotension , but probably don't need to. What is a low blood pressure reading? What causes low blood pressure?
Is low blood pressure dangerous? How is low blood pressure treated? Most people with low blood pressure will not need treatment.
What is blood pressure? What is a normal blood pressure reading? What is high blood pressure hypertension? What high blood pressure can do How lifestyle changes can lower your blood pressure Medicines for high blood pressure Using a home blood pressure monitor DVD guide to blood pressure. Blood pressure is usually lowest at night and rises sharply on waking. What's considered low blood pressure for you may be normal for someone else.
Most doctors consider blood pressure too low only if it causes symptoms. Some experts define low blood pressure as readings lower than 90 mm Hg systolic or 60 mm Hg diastolic. If either number is below that, your pressure is lower than normal. A sudden fall in blood pressure can be dangerous. A change of just 20 mm Hg — a drop from systolic to 90 mm Hg systolic, for example — can cause dizziness and fainting when the brain fails to receive an adequate supply of blood.
And big plunges, such as those caused by uncontrolled bleeding, severe infections or allergic reactions, can be life-threatening. Doctors often break down low blood pressure hypotension into categories, depending on the causes and other factors. Some types of low blood pressure include:.
Low blood pressure on standing up orthostatic, or postural, hypotension. This is a sudden drop in blood pressure when you stand up from a sitting position or after lying down.
Gravity causes blood to pool in your legs when you stand. Ordinarily, your body compensates by increasing your heart rate and constricting blood vessels, thereby ensuring that enough blood returns to your brain.
But in people with orthostatic hypotension, this compensating mechanism fails and blood pressure falls, leading to dizziness, lightheadedness, blurred vision and even fainting. Orthostatic hypotension can occur for various reasons, including dehydration, prolonged bed rest, pregnancy, diabetes, heart problems, burns, excessive heat, large varicose veins and certain neurological disorders.
A number of medications also can cause orthostatic hypotension, particularly drugs used to treat high blood pressure — diuretics, beta blockers, calcium channel blockers and angiotensin-converting enzyme ACE inhibitors — as well as antidepressants and drugs used to treat Parkinson's disease and erectile dysfunction. Orthostatic hypotension is especially common in older adults, but it also affects young, otherwise healthy people who stand up suddenly after sitting with their legs crossed for long periods or after squatting for a time.
It's also possible to have delayed orthostatic hypotension, with signs and symptoms developing 5 to 10 minutes after a change in posture. Types of low blood pressure There are 3 main types of low blood pressure. Orthostatic hypotension Orthostatic hypotension, also called postural hypotension , is an inability to regulate blood pressure quickly. Neurally mediated hypotension Neurally mediated hypotension is low blood pressure that is often brought on by stress, pain or prolonged standing especially in a hot environment.
Severe low blood pressure due to shock Shock is a condition where there is a severe drop in blood pressure related to a serious problem, such as massive blood loss, sepsis an overwhelming bacterial infection or anaphylaxis a severe allergic reaction. What causes low blood pressure? Dehydration due to fluid loss either from sweating in very hot weather or from vomiting and diarrhoea. Certain medicines , such as medicines used to treat high blood pressure, some angina medicines, diuretics, other heart medicines, some medicines used for erectile dysfunction and some antidepressants.
Conditions affecting the heart and lungs , such as a faulty heart valve, abnormal heart rhythms, pulmonary embolism, the weakening of the heart muscle following a heart attack myocardial infarction , or generalised weakness of the heart muscle due to conditions such as cardiomyopathy.
Anaemia a reduced number of red blood cells or a lack of haemoglobin, the substance in red blood cells which transports oxygen around the body.
Prolonged immobility bed rest for an extended period due to illness or injury. Septic shock a severe infection. Anaphylaxis a severe allergic reaction. Diagnosis Your doctor will ask about your symptoms and perform a physical examination, including a blood pressure check.
Tests Depending on your symptoms and physical examination, initial tests your doctor may recommend include: Your doctor may refer you to a specialist for further evaluation and treatment if necessary.
Treatment of low blood pressure Low blood pressure may or may not require treatment, depending on the cause. Treatment of orthostatic hypotension Orthostatic hypotension may occasionally require treatment with medicines.
Stand up slowly, especially if you have been sitting or lying down for a long time. Move your legs around before changing positions. Drink plenty of fluids to avoid becoming dehydrated. Reduce your intake of alcohol. Alcohol can contribute to low blood pressure. Avoid very hot showers and baths. If you get low blood pressure after eating, sit still or lie down after meals, and try eating smaller amounts more frequently. If you have had a period of prolonged bed rest, slowly increase the amount of time you spend sitting up.
Treatment of neurally mediated hypotension Lifestyle measures can help treat this type of low blood pressure. Sometimes medicines are prescribed to normalise blood pressure. Treatment of sudden severe hypotension shock Serious conditions that cause a sudden drop in blood pressure need urgent medical treatment in hospital.
Depending on the cause and severity of the condition, these may include: When to see the doctor If you have had episodes where you feel faint or have fainted, see your doctor. Low blood pressure hypotension updated 2 May National Heart, Lung and Blood Institute.
Low Blood Pressure (Hypotension) Signs and Symptoms
Learn more about the types and causes of low blood pressure, or hypotension, from the experts at WebMD. Low blood pressure symptoms, causes & low blood pressure treatments from the UK Blood Pressure Charity. And the pushing of the blood against the artery walls is called blood pressure. Low blood pressure is good in most cases. But low blood pressure can.