What does low blood pressure indicate?
Low blood pressure occurs when blood pressure is much lower than normal. This means the heart, brain, and other parts of the body do not get enough blood. Normal blood pressure is mostly between 90/60 mmHg and 120/80 mmHg. The medical name for low blood pressure is hypotension.
What Causes Low Blood Pressure?
- Pregnancy.
- Hormonal problems such as an underactive thyroid (hypothyroidism), diabetes, or low blood sugar (hypoglycemia)
- Some over-the-counter medications.
- Some prescription medicines such as for high blood pressure, depression or Parkinson's disease.
- Heart failure.
Symptoms And Causes Of Low Blood Pressure
Many different conditions and situations can cause low blood pressure, from standing up too fast to being pregnant. Sometimes, low blood pressure is linked to an underlying problem. That’s why it’s important to see your doctor right away if you experience the signs of low blood pressure.
Symptoms of low blood pressure can include:
- Dizziness
- Fainting
- Dehydration
- Lack of concentration
- Blurred vision
- Nausea
- Cold, clammy and pale skin
- Rapid, shallow breathing
- Fatigue
- Depression
Low blood pressure can be a sign of serious heart, endocrine or neurological conditions. If left untreated, the brain and other vital organs do not get the oxygen and nutrients they need. In extreme cases, this can cause shock, a life-threatening condition.
Underlying causes of low blood pressure
Low blood pressure can occur with:
Prolonged bed rest
Pregnancy: During the first 24 weeks of pregnancy, it’s common for blood pressure to drop.
Decreases in blood volume: A decrease in blood volume can also cause blood pressure to drop. A significant loss of blood from major trauma, dehydration or severe internal bleeding reduces blood volume, leading to a severe drop in blood pressure.
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. Other prescription and over-the-counter drugs may cause low blood pressure when taken in combination with high blood pressure medications.
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. Your heart may not be able to circulate enough blood to meet your body’s needs.
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.
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. The bacteria then produce toxins that affect blood vessels, leading to a profound and life-threatening decline 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. This type of shock is characterized by breathing problems, hives, itching, a swollen throat and a sudden, dramatic fall in blood pressure.
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 condition primarily affects young people and occurs because of a miscommunication between the heart and the brain.
Nutritional deficiencies: A lack of the essential vitamins B-12 and folic acid can cause anemia, which in turn can lead to low blood pressure.
