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 110 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
It doesn’t always cause symptoms, but you may need treatment if it does. Within certain limits, the lower your blood pressure reading is, the better. There is also no specific number at which day-to-day blood pressure is considered too low, as long as none of the symptoms of trouble are present.
If you’re 40 to 74 years old, you should have your blood pressure checked at least once every 5 years.
SYMPTOMS OF LOW BLOOD PRESSURE
Most doctors will only consider chronically low blood pressure as dangerous if it causes noticeable signs and symptoms, such as:
- Dizziness or lightheadedness
- Fainting (syncope)
- Lack of concentration
- Blurred vision
- Cold, clammy, pale skin
- Rapid, shallow breathing
- Dehydration and unusual thirst
- Dehydration can sometimes cause blood pressure to drop. However, dehydration does not always cause low blood pressure. Fever, vomiting, severe diarrhea, overuse of diuretics and strenuous exercise can all lead to dehydration, a potentially serious condition in which your body loses more water than you take in. Even mild dehydration (a loss of as little as 1 percent to 2 percent of body weight) can cause weakness, dizziness and fatigue.
If you get symptoms when you stand up or suddenly change position, you may have postural hypotension.
UNDERLYING CAUSES OF LOW BLOOD PRESSURE
Low blood pressure can occur with:
- Prolonged bed rest
- Pregnancy: During the first 24 weeks of pregnancy, it’s common for blood pressure to drop.
- Decreases in blood volume: A decrease in blood volume can also cause blood pressure to drop. A significant loss of blood from major trauma, dehydration or severe internal bleeding reduces blood volume, leading to a severe drop in blood pressure.
- Certain medications: A number of drugs can cause low blood pressure, including diuretics and other drugs that treat hypertension; heart medications such as beta blockers; drugs for Parkinson’s disease; tricyclic antidepressants; erectile dysfunction drugs, particularly in combination with nitroglycerine; narcotics and alcohol. Other prescription and over-the-counter-drugs may cause low blood pressure when taken in combination with high blood pressure medications.
- Heart problems: Among the heart conditions that can lead to low blood pressure are an abnormally low heart rate (bradycardia) problems with heart valves, heart attackand heart failure. Your heart may not be able to circulate enough blood to meet your body’s needs.
- Endocrine problems: Such problems include complications with hormone-producing glands in the body’s endocrine systems; specifically, an underactive thyroid (hypothyroidism), parathyroid disease, adrenal insufficiency (Addison’s disease), low blood sugar and, in some cases, diabetes.
- Severe infection (septic shock): Septic shock can occur when bacteria leave the original site of an infection (most often in the lungs, abdomen or urinary tract) and enter the bloodstream. The bacteria then produce toxins that affect blood vessels, leading to a profound and life-threatening decline in blood pressure.
- Allergic reaction (anaphylaxis): Anaphylactic shock is a sometimes-fatal allergic reaction that can occur in people who are highly sensitive to drugs such as penicillin, to certain foods such as peanuts or to bee or wasp stings. This type of shock is characterized by breathing problems, hives, itching, a swollen throat and a sudden, dramatic fall in blood pressure.
- Neurally mediated hypotension: Unlike orthostatic hypotension, this disorder causes blood pressure to drop after standing for long periods, leading to symptoms such as dizziness, nausea and fainting. This condition primarily affects young people and occurs because of a miscommunication between the heart and the brain.
- Nutritional deficiencies: A lack of the essential vitamins B-12 and folic acid can cause anemia, which in turn can lead to low blood pressure.
TYPES OF LOW BLOOD PRESSURE
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. This might be a milder form of the condition, or it could be an early stage of it.
- Low blood pressure after eating (postprandial hypotension). This sudden drop in blood pressure after eating affects mostly older adults.
- Blood flows to your digestive tract after you eat. Ordinarily, your body increases your heart rate and constricts certain blood vessels to help maintain normal blood pressure. But in some people these mechanisms fail, leading to dizziness, faintness and falls.
- Postprandial hypotension is more likely to affect people with high blood pressure or autonomic nervous system disorders such as Parkinson’s disease.
- Lowering the dose of blood pressure drugs and eating small, low-carbohydrate meals might help reduce symptoms.
- Low blood pressure from faulty brain signals (neurally mediated hypotension). This disorder, which causes a blood pressure drop after standing for long periods, mostly affects young adults and children. It seems to occur because of a miscommunication between the heart and the brain.
- Low blood pressure due to nervous system damage (multiple system atrophy with orthostatic hypotension). Also called Shy-Drager syndrome, this rare disorder causes progressive damage to the autonomic nervous system, which controls involuntary functions such as blood pressure, heart rate, breathing and digestion. It’s associated with having very high blood pressure while lying down.
HOW TO CHECK YOUR BLOOD PRESSURE
You can check your blood pressure:
- by asking if your pharmacist can do it
- by asking your practice nurse or GP to do it
- at home yourself using a home blood pressure monitor
Low blood pressure (hypotension) can occur in anyone, though certain types of low blood pressure are more common depending on your age or other factors:
- Drops in blood pressure on standing or after eating occur primarily in adults older than 65. Neurally mediated hypotension primarily affects children and younger adults.
- People who take certain medications, for example, high blood pressure medications such as alpha blockers, have a greater risk of low blood pressure.
- Certain diseases. Parkinson’s disease, diabetes and some heart conditions put you at a greater risk of developing low blood pressure.
CONTACT KENOCH HG HERBAL CLINIC IF
- you have low blood pressure and keep getting symptoms such as dizziness
TREATMENT FOR LOW BLOOD PRESSURE DEPENDS ON THE CAUSE
If a cause can be found, your GP will be able to recommend treatment to ease your symptoms.
For example, they may suggest:
- changing medication or altering your dose, if medication is the cause
- wearing support stockings – this can improve circulation and increase blood pressure
Medication to increase blood pressure is rarely needed because simple lifestyle measures or treating the underlying cause is usually effective.
HOW TO EASE LOW BLOOD PRESSURE SYMPTOMS YOURSELF
- get up slowly from sitting to standing
- take care when getting out of bed – move slowly from lying to sitting to standing
- raise the head of your bed by about 15cm (6 inches) with bricks or heavy books
- eat small, frequent meals – lying down or sitting still for a while after eating may also help
- increase the amount of water you drink
- do not sit or stand for long periods
- do not bend down or change posture suddenly
- do not drink caffeinated drinks at night
- do not drink too much alcohol
Low blood pressure. NHS. https://www.nhs.uk/conditions/low-blood-pressure-hypotension/. Accessed on May 10, 2019
Low blood pressure (hypotension). Mayoclinic. https://www.mayoclinic.org/diseases-conditions/low-blood-pressure/symptoms-causes/syc-20355465. Accessed on May 10, 2019
Low Blood Pressure – When Blood Pressure Is Too Low. American heart association. https://www.heart.org/en/health-topics/high-blood-pressure/the-facts-about-high-blood-pressure/low-blood-pressure-when-blood-pressure-is-too-low. Accessed on May 10, 2019