Low Blood Pressure

Pressure applied by the blood on the wall of the vessels especially on the walls of arteries is called Blood Pressure. Normal blood pressure ranges in between 120/80 mm Hg. Blood pressure below the normal range is known as Low Blood Pressure. Low blood pressure is also known as Hypotension.

Types of Hypotension

  • Orthostatic, or postural Hypotension, Low blood pressure on standing up. This is a sudden drop in blood pressure when you stand up from a sitting position or after lying down.
  • Postprandial Hypotension, Low blood pressure after eating. This is a sudden drop in blood pressure after eating affects mostly older adults.
  • Neurally mediated Hypotension, Low blood pressure from faulty brain signals. 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.
  • 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.
Types of Hypotension

Risk factors of Hypotension

Hypotension occurs in any anyone, the common factors causing hypotension are:

  • Age, mostly adults above 65 are on risk of hypotension.
  • Medications, certain types of medicine also increase risk of hypotension.
  • Certain diseases, Parkinson’s Disease, Diabetes or some other Heart Diseases may also increase risk of Hypotension.
Risk factors causing Hypotension

Symptoms of Hypotension

Mostly low blood pressure signals an underlying conditions, especially when hypotension occurs suddenly or is accompanied by following sign and sypmtoms: 

  • Dizziness or lightheadedness.
  • Fainting (syncope).
  • Blurred vision.
  • Nausea.
  • Fatigue.
  • Lack of concentration.

Extreme Hypotension can cause life threatening conditions, which include sign and symptoms like: 

  • Confusion, especially in older people.
  • Cold, clammy, pale skin.
  • Rapid, shallow breathing.
  • Weak and rapid pulse.
Symptoms of Hypotension

Causes of Hypotension

There are many causes for the Hypotension. Some medical conditions that can cause Hypotension are:

  • Pregnancy.
  • Heart problems. 
  • Endocrine problems.
  • Dehydration.
  • Blood loss.
  • Severe infection (septicemia).
  • Severe allergic reaction (anaphylaxis).
  • Lack of nutrients in your body.

Medicines that may cause Hypotension are:

  • Water pills (diuretics), such as Lasix, Maxzide, Microzide, and others.
  • Alpha Blockers, such as Minipress.
  • Beta Blockers, such as Tenormin, Inderal, Innopran XL, and others.
  • Drugs for Parkinson’s Disease, such as Mirapex or those containing levodopa.
  • Antidepressants, such as Silenor, Tofranil and others.
  • Drugs for Erectile Dysfunction, such as Revatio, Viagra, Adcirca, Cialis and others.
Causes of Hypotension


Blood pressure is measured by an instrument having a inflatable cuff tied on Patient’s arm near elbow, and measure blood pressure by pressure-measuring gauge. The instrument used to measure blood pressure is called Sphygmomanometer.

If patient’s blood pressure is lower then the normal limits, then it is said to be hypotensive patient. Physician should also recommend these lab investigations to make his diagnosis in proper direction:

  • Blood tests.
  • Electrocardiogram (ECG).
  • Echocardiogram.
  • Stress test.
  • Valsalva maneuver.
  • Tilt table test.
Lab Investigations for Low Blood Pressure