What causes low blood pressure ?!

What causes low blood pressure ?

What causes low blood pressure ? and what to do if a have it?

Hypotension is the medical term for low blood pressure (less than 90/60). Normal blood pressure is usually in the range of 120/80 (systolic/diastolic). In healthy people, especially athletes, low blood pressure is a sign of good cardiovascular (heart and blood vessel) health. But low blood pressure can be a signal of an underlying problem — especially in the elderly. In this population, low blood pressure may cause inadequate blood flow to the heart, brain and other vital organs.

What Causes It?
The cause of low blood pressure isn't always clear. It may be associated with the following:
Pregnancy.
Hormonal problems such as an underactive thyroid (hypothyroidism), overactive thyroid (hyperthyroidism), diabetes, and low blood sugar (hypoglycemia).
Many over-the-counter medications.
Overdose of high blood pressure drugs.
Heart failure.
Heart arrhythmias (abnormal heart rhythms).
Widening, or dilation, of the blood vessels.
Heat exhaustion or heat stroke.
Liver disease.

Sudden drops in blood pressure can be life-threatening. Causes of this type of hypotension include:

Loss of blood (bleeding).
Low body temperature.
High body temperature.
Heart muscle disease causing heart failure.
Sepsis, a severe blood infection.
Severe dehydration.
A reaction to medication.
Severe allergic reaction (anaphylaxis).

Postural hypotension can happen to anyone for a variety of reasons, such as dehydration, lack of food, prolonged standing in the heat, or being generally run down. It can also be influenced by genetic make-up, aging, medication, dietary and psychological factors, and acute triggers, such as infection and allergy.

Postural hypotension occurs most frequently in people who are taking drugs to control high blood pressure (hypertension). It can also be related to pregnancy, strong emotions, hardening of the arteries (atherosclerosis), or diabetes. The elderly are particularly affected, especially those who have high blood pressure or autonomic nervous dysfunction. Postprandial (after meals) hypotension is estimated to affect up to one-third of elderly people and is a common cause of dizziness and falls after eating.

Several drugs are commonly associated with postural hypotension. These medications can be divided into two major categories 1) medications and 2) other common causes:

Drugs used to treat high blood pressure, such as diuretics, beta-blockers, calcium channel blockers, and angiotensin-converting enzyme (ACE) inhibiting drugs.
Drugs that have hypotension as a side effect, including nitrates, drugs for Parkinson's disease, antipsychotics, neuroleptics, anti-anxiety agents, sedative-hypnotics, and tricyclic antidepressants.

Common causes of naturally occurring postural hypotension include:

Dehydration and electrolyte loss, which may result from another condition, such as diarrhea or vomiting or excessive blood loss during female menstruation.
Age-associated decline in blood pressure regulation, which may be worsened by certain health conditions or medications.

Common causes of pathologic (attributable to a disease)
postural hypotension include:

Central nervous system disorders, such as Shy-Drager syndrome. (multiple system neuropathy)
Peripheral neuropathy and autonomic neuropathy (nerve problems), such as may be caused by diabetes.
Cardiovascular disorders.
Alcoholism.
Nutritional diseases.
Less common causes include diseases such as amyloidosis (caused by deposits of a waxy substance called amyloid in the body), vitamin deficiencies, spinal cord injuries, and neuropathies associated with cancer, particularly lung cancer or pancreatic cancer.

What Are the Treatments?
If you have an underlying medical problem that causes low blood pressure, seek treatment for the underlying condition. For many people, chronic low blood pressure can be effectively treated with diet and lifestyle changes.

Initially, your doctor may counsel you to increase your blood pressure by making these simple changes:

Eat a diet higher in salt.
Drink lots of non-alcoholic fluids — a minimum of eight glasses per day. Sports drinks that are high in sodium and potassium are recommended, especially during exercise or in hot weather.
Consume extra salt and drink more fluids during hot weather and while sick with a viral illness, such as a cold or the flu.
Have your doctor evaluate your prescription and over-the-counter medications to identify any that may be causing your symptoms.
Get regular exercise to promote blood flow.
Be careful when rising from a prone or sitting position. To improve circulation, stretch your feet back and forth before standing up. Then proceed slowly. When getting out of bed, sit upright on the edge of the bed for a few minutes before standing.
Elevate the head of your bed at night by 5-20 degrees by placing bricks or blocks under the head of bed.
Avoid heavy lifting.
Avoid straining while on the toilet.
Avoid prolonged exposure to hot water, such as hot showers and spas. If you get dizzy, sit down. It may be helpful to keep a chair or stool in the shower in case you need to sit; to help prevent injury, use a chair or stool that is specifically designed for showers or bath tubs.
To avoid problems with low blood pressure after meals, try eating smaller, more frequent meals and resting after eating to lessen episodes of dizziness. Avoid taking low blood pressure drugs before meals.
If needed, use elastic support (compression) stockings that cover the calf and thigh. These may help restrict blood flow to the legs, thus keeping more blood in the upper body.
If tolerated, drink coffee in the morning. The amount of caffeine normally found in two cups of coffee (250 mg) can decrease low blood pressure in young adults and can be safely used by older adults as well. If these measures don't lessen the problem, you may need medication.

The following medications have proved effective in treating low blood pressure:

Fludrocortisone. Fludrocortisone is a mineralocorticosteroid that appears to be effective for most types of postural hypotension, or low blood pressure. It works by promoting sodium retention by the kidney, thereby causing fluid retention and some swelling, which is necessary to improve blood pressure. But this sodium retention also causes a loss of potassium. Therefore, when taking fludrocortisone, it's important to also take adequate amounts of potassium each day. Fludrocortisone has none of the anti-inflammatory properties of cortisone or prednisone and it is not a muscle-building agent.

Midodrine. Midodrine activates receptors on the arterioles (smallest arteries) and veins to produce an increase in blood pressure. Studies show that it is effective in improving standing blood pressure in people with postural hypotension related to nervous system dysfunction, such as those with Shy-Drager syndrome.

Click these links for more info:
http://www.webmd.com/heart/understanding...
http://www.webmd.com/hypertension-high-b...