Low Blood Pressure (Hypotension) - Causes, Signs & Symptoms

blood pressure is the pressure of blood pushing against the walls of the arteries it is measured using two numbers the first number called systolic blood pressure measures the pressure in the arteries when the heart beats the second number called diastolic blood pressure measures the pressure in the arteries when the heart rests between beats normal blood pressure is equal to 120 mmhg systolic over 80 mmhg diastolic low blood pressure or hypotension is defined as a blood pressure less than 90 systolic over 60 diastolic major causes of low blood pressure include the following prolonged bed rest pregnancy decreased blood volume mainly due to bleeding and dehydration certain medications including diuretics beta blockers drugs used in Parkinson's disease tricyclic antidepressants drugs used for erectile dysfunction narcotics and alcohol all cardiac causes including heart failure endocrine problems including hypothyroidism Addison's disease low blood sugar and diabetes infective causes including sepsis severe allergic reactions such as anaphylaxis and nutritional deficiencies such as vitamin B12 and folate deficiency which can lead to anemia and hypotension signs and symptoms of hypotension include the following dizziness and lightheadedness nausea and vomiting difficulty in concentrating rapid heartbeat and palpitations blurred vision faintishness rapid shallow breathing and fatigue