This condition primarily affects young people and occurs because of a miscommunication between the heart and the brain. Neurally mediated hypotension: Unlike orthostatic hypotension, this disorder causes blood pressure to drop after standing for long periods, leading to symptoms such as dizziness, nausea and fainting.This type of shock is characterized by breathing problems, hives, itching, a swollen throat and a sudden, dramatic fall in blood pressure. Allergic reaction (anaphylaxis): Anaphylactic shock is a sometimes-fatal allergic reaction that can occur in people who are highly sensitive to drugs such as penicillin, to certain foods such as peanuts or to bee or wasp stings.The bacteria then produce toxins that affect blood vessels, leading to a profound and life-threatening decline in blood pressure. Severe infection (septic shock): Septic shock can occur when bacteria leave the original site of an infection (most often in the lungs, abdomen or urinary tract) and enter the bloodstream.Endocrine problems: Such problems include complications with hormone-producing glands in the body’s endocrine systems specifically, an underactive thyroid (hypothyroidism), parathyroid disease, adrenal insufficiency (Addison’s disease), low blood sugar and, in some cases, diabetes.Your heart may not be able to circulate enough blood to meet your body’s needs. Heart problems: Among the heart conditions that can lead to low blood pressure are an abnormally low heart rate ( bradycardia), problems with heart valves, heart attack and heart failure.Other prescription and over-the-counter drugs may cause low blood pressure when taken in combination with high blood pressure medications. Certain medications: A number of drugs can cause low blood pressure, including diuretics and other drugs that treat hypertension heart medications such as beta blockers drugs for Parkinson’s disease tricyclic antidepressants erectile dysfunction drugs, particularly in combination with nitroglycerine narcotics and alcohol.A significant loss of blood from major trauma, dehydration or severe internal bleeding reduces blood volume, leading to a severe drop in blood pressure.
Decreases in blood volume: A decrease in blood volume can also cause blood pressure to drop.Pregnancy: During the first 24 weeks of pregnancy, it’s common for blood pressure to drop.Even mild dehydration (a loss of as little as 1 percent to 2 percent of body weight) can cause weakness, dizziness and fatigue. Fever, vomiting, severe diarrhea, overuse of diuretics and strenuous exercise can all lead to dehydration, a potentially serious condition in which your body loses more water than you take in. However, dehydration does not always cause low blood pressure.