Organ or part of body involved: Heart, blood vessels (arteries), kidneys.

Symptoms and indications: Low blood pressure is often accompanied by: Chest pain; Shortness of breath; Irregular heartbeat; Fever higher than 101°F (38.3°C); Headache; Stiff neck; Severe upper back pain; Cough with phlegm; Prolonged diarrhoea or vomiting; Inability to eat or drink; Burning micturition; Foul-smelling urine; Adverse effect of medications; Acute, life-threatening allergic reaction; Dizziness, or light-headedness; Seizures; and Loss of consciousness.

Causes and risk factors: Low blood pressure is commonly caused by drugs such as the following : Medications used for surgery; Anti-anxiety agents; Treatment for high blood pressure; Diuretics; Heart medicines; Some antidepressants; Narcotics; Analgesics; and Alcohol.

Other causes of low blood pressure include the following: Dehydration; Heart failure; Heart attack; Changes in heart rhythm (arrhythmias); Fainting; Anaphylaxis (a life-threatening allergic response); Shock (from severe infection, stroke, anaphylaxis, major trauma, or heart attack); and Advanced diabetes.

Another common cause type of low blood pressure is orthostatic hypotension, which results from a sudden change in body position, usually from lying down to an upright position.