Blood pressure is the pressure of the blood against the walls of the arteries (blood vessels) during and after each beat of the heart, differentiated as systolic and diastolic pressure, but when both of these reading are much lower than usual, hypotension occurs.

There are many contributors to low blood pressure, the most commonly associated to this condition are drugs like medications used for surgery, diuretics, heart medicament, anti-anxiety agents, some type or antidepressants and treatments for high blood pressure or coronary heart disease (CHD).

Although often associated to high blood pressure, alcohol may cause a sudden low blood pressure, the same as diverse narcotic analgesics, including aspirin, ibuprofen, naproxen and acetaminophen. Analgesics are not risky by themselves, just dangerous if administered when blood pressure is falling.

However, other causes of low blood pressure may include dehydration, heart failure and heart attack, changes in heart rhythm, known as arrhythmias, fainting, advanced diabetes or anaphylaxis, which is a life-threatening allergic response.

Because this is a dangerous condition, time is an important factor. Call the doctor immediately if you have black or maroon stools, feel dizzy, lightheaded, or faint, if you have shortness of breath, chest pain, an irregular heartbeat, or if you are running a fever higher than 101º F, headache, stiff neck, and severe upper back pain.

In extreme cases, low blood pressure leads to shock, as a result of severe infection, severe allergic reaction (anaphylaxis), major trauma, heart attack or stroke. Hypotension can only be diagnosed by frequent monitoring of vital signs, including pulse, rate of breathing, blood pressure and temperature.

Low blood pressure cannot be generalized, a blood pressure level that is low for one person may be normal for another, this is the reason why other aspects and vital signs should be examined, analyzing how the blood pressure changes from the normal condition.

Chronic low blood pressure is generally never serious. People who suffer from low blood pressure may have frequent episodes of hypotension, but lower risk of heart disease, stroke, and kidney disease in comparison with people suffering from high blood pressure.

The typical and more dangerous problems occur when blood pressure drops suddenly, depriving the brain of an adequate blood supply, leading to dizziness or lightheadedness. The incidence of low blood pressure also increases with age, as it does with high blood pressure.

Moreover, blood flow in the brain also tends to decline, as people get older, due to plaque buildup in blood vessels. Postural hypotension also increases with age, with around 10 to 20% of elderly people suffering from this condition.