Hypotension, also known as low blood pressure, is condition in which the blood pressure is abnormally low, either because of reduced blood volume or because of increased blood-vessel capacity. Though not in itself an indication of ill health, it often accompanies disease.
The heart pumps blood around the body through the blood vessels. Blood pressure is the amount of force exerted on the artery walls by the pumping blood. Blood pressure varies according to environmental demands. For example, it rises during physical exertion and drops in extreme heat. Low blood pressure is only a problem if it has a negative impact on the body. For example, vital organs (particularly the brain) may be starved of oxygen and nutrients if the blood pressure is too low for that particular person.
What is blood pressure?
Blood pressure is written as two numbers – for example, 120 over 80 millimeters of mercury. The first number is the systolic pressure. This is the pressure in the arteries when the heart beats and fills them with blood. The second number is the diastolic pressure. This is the pressure in the arteries when the heart rests between beats.
Anybody with a reading if 90/60 mmHg or lower is regarded as having hypotension (low blood pressure). People with low blood pressure have some protection from factors which raise blood pressure to undesirable levels. However, low blood pressure may be a sign of an underlying problem, and can cause unpleasant symptoms.
Types of Hypotension
- Acute – Acute hypotension is a sudden drop in the BP that may be life-threatening.
- Constitutional – Constitutional hypotension means that the BP is lower than it should be most or all of the time. This is a chronic condition that occurs with no known medical cause.
- Orthostatic – Orthostatic hypotension normally occurs when a person stands up from a sitting or lying position. It is also called postural hypotension.
- Postprandial – Postprandial hypotension means the BP becomes too low after a meal. The BP may drop within 2 hours after a person eats, and is more common when the meal is high in carbohydrates.
Causes
Low blood pressure has many different causes including:
- Emotional stress, fear, insecurity or pain (the most common causes of fainting)
- Dehydration, which reduces blood volume
- The body’s reaction to heat, which is to shunt blood into the vessels of the skin, leading to dehydration
- Blood donation
- Internal bleeding, such as a perforated stomach ulcer
- Blood loss from trauma, such as a road accident or deep cut
- Pregnancy
- Medications for high blood pressure
- Diuretics, which produce fluid loss
- Medications for depression
- Medications for certain heart conditions
- Allergic reaction to certain drugs or chemicals
- Some forms of infection, such as toxic shock syndrome
- Heart disease, which can hamper the pumping action of the heart muscle
- Some nervous system disorders, such as Parkinson’s disease
- Addison’s disease (where the adrenal glands fail to produce sufficient blood-pressure maintaining hormones)
- Anemia or blood loss
- Nervous system, heart, or adrenal disorders
- Dehydration from not drinking enough liquids, frequent vomiting, diarrhea, or severe burns
- Some medicines, such as those used to treat high blood pressure, heart conditions, pain, depression, or cancer
- A blood infection (sepsis)
Who is at risk?
- Hypotension can affect people of all ages. However, people in certain age groups are more likely to have certain types of hypotension.
- Older adults are more likely to have orthostatic and postprandial hypotension. Children and young adults are more likely to have neurally mediated hypotension.
- People who take certain medicines—such as diuretics (“water pills”) or other high blood pressure medicines—are at increased risk for hypotension. Certain conditions also increase the risk for hypotension. Examples include central nervous system disorders (such as Parkinson’s disease) and some heart conditions.
- Other risk factors for hypotension include being immobile (not being able to move around very much) for long periods, being out in the heat for a long time, and pregnancy. Hypotension during pregnancy is normal and usually goes away after birth.
Symptoms
If blood pressure is so low that the supply of blood to the brain and other vital organs is insufficient the patient will need medical attention. Severe hypotension is caused by an underlying illness or condition.
- Below are the most common symptoms of hypotension:
- Blurred vision
- Cold, clammy, pale skin
- Depression
- Dizziness
- Fainting
- Fatigue
- General feeling of weakness
- Nausea
- Palpitations
- Rapid, shallow breathing
- Thirst
There is a particular type of low blood pressure called ‘postural hypotension’ or ‘orthostatic hypotension’. In this condition, a person’s blood pressure is normal when they are sitting or lying down, but it drops suddenly when they stand, making them feel dizzy or lightheaded.
Complications
Falls due to low blood pressure in older adults can lead to a broken hip or spine fracture. These injuries can reduce a person’s health and ability to move around
Sudden severe drops in the blood pressure starves the body of oxygen. This can lead to damage of the heart, brain, and other organs. This type of low blood pressure can be life threatening if not treated right away.
Treatment
Medications –
Alpha-adrenoreceptor agonists – These medicines may increase the BP and decrease the symptoms.
Steroids – This medicine helps prevent salt loss from the body. Steroids may also help increase the amount of fluid in the body and raise the BP.
Vasopressors – These medicines help constrict (make smaller) the blood vessels and increase the BP. Vasopressor medicines may increase the blood flow to the brain and help decrease the symptoms.
Antidiuretic hormone – This medicine helps control the BP and helps decrease the need to urinate during the night.
Antiparkinson medicine – This medicine may help increase tjhe standing BP and decrease the symptoms.
Compression stockings or abdominal binder -These may help blood return to the heart and decrease hypotension.
IV fluids – These may be used to increase the BP if a person is dehydrated or have blood loss or sepsis.
Alternative Treatment
DHEA – DHEA (dehydroepiandrosterone) is a hormone that is produced by the adrenal glands. Unclear scientific evidence exists surrounding the safety or effectiveness of DHEA supplementation in patients with septicemia (serious bacterial infections in the blood), which may lead to hypotension.
Iodine -Rinsing with povidone-iodine may help reduce the incidence and severity of septicemia (serious bacterial infections in the blood).
Ephedra – Chemicals in ephedra can stimulate the heart, increase heart rate, and raise blood pressure. Ephedrine, a component of ephedra, is sometimes used in hospitals to help control blood pressure.
Hawthorn – Hawthorn (Crataegus spp.), a flowering shrub of the rose family has an extensive history of use in cardiovascular disease dating back to the 1st Century. Preliminary study suggests that fresh hawthorn berries may improve orthostatic hypotension.
Selenium – Selenium is a mineral found in soil, water, and some foods. Study results of selenium supplementation in patients with sepsis (severe bacterial infection in the blood) are mixed.
Adrenal extract – Adrenal extracts come from the adrenal glands of cows, pigs, or sheep. It has been suggested that adrenal extract may help treat patients with hypotension.
Rhubarb – Limited available study indicates that rhubarb may be helpful in treating systemic inflammation reaction syndrome (SIRS).
Ginger – The underground stems (called rhizomes) and above ground stems of ginger have been used in Chinese, Japanese, and Indian medicine for hundreds of years. There have been anecdotal reports of reduced blood pressure in people who took ginger.
Hydrotherapy – Hydrotherapy is broadly defined as the external application of water in any form or temperature for healing purposes. It may include immersion in a bath or body of water (such as the ocean or a pool), use of water jets, douches, application of wet towels to the skin, or water birth.
Physical therapy – The goal of physical therapy is to improve mobility, restore function, reduce pain, and prevent further injury. A variety of techniques, including exercises, stretches, traction, electrical stimulation, and massage, are used during physical therapy sessions.
Reference –
http://www.healthtranslations.vic.gov.au/bhcv2/bhcpdf.nsf/ByPDF/Hypotension/$File/Hypotension.pdf
http://www.britannica.com/science/hypotension
http://www.bloodpressureuk.org/BloodPressureandyou/Yourbody/Lowbloodpressure
https://www.medschool.lsuhsc.edu/emergency_medicine/docs/EMP%20Ultrasound%20&%20Hypotension.pdf
http://emedicine.medscape.com/article/1154266-overview
http://www.aafp.org/afp/2011/0901/p527.html
http://www.pdf.org/en/orthostatic_hypotension_pd