What Are the Main Types and Reasons for Low Blood Pressure?
Introduction on Low BP
Blood pressure is the pressure that is exerted by the blood on the walls of the blood vessels. In an adult, the normal blood pressure is 120/80 mm of Hg, and the instrument used to measure blood pressure is known as a sphygmomanometer. The blood pressure level which is lower than the normal blood pressure is known as Low Blood Pressure (Low Bp) or Hypotension. The low blood pressure level is 90/60 mm of Hg or below. It is not concerned as a serious illness issue unless and until someone starts experiencing major symptoms after changing their body posture.
Types of Low Blood Pressure
These are of 4 types categorized according to the blood pressure drops :
Orthostatic - It is most common in all ages. It occurs when you change your position from lying down to standing or sitting. A sudden transition causes orthostatic blood pressure.
Postprandial - It is a drop in blood pressure which happens exactly after eating. This occurs significantly in older people who are suffering from Parkinson's disease.
Naturally Mediated - It is a drop in blood pressure when you stand for a long time. This occurs mainly in children than in adults.
Severe Blood Pressure - This occurs when a person experiences a sudden shock. It occurs when organs of the body do not get enough blood and oxygen for proper functioning. This is a very serious condition that has to be treated immediately.
Postural Hypotension
Postural Hypotension is a medical condition that occurs either due to lying down or standing for a long time. This can also happen due to a variety of reasons like dehydration, lack of food, or being overly fatigued. This can also happen due to genetic makeup, aging, medication, dietary and physiological factors, and cute triggers such as allergy.
This most commonly occurs in those who take drugs most frequently to control high blood pressure. It may also happen in pregnancy, psychological problems, hardening of the arteries, or diabetes. The old age people are more significantly affected who have high blood pressure or autonomic nervous system dysfunction.
Reasons for Low Blood Pressure
The causes of hypotension cannot be defined clearly but may due to the following causes:
Dehydration - It is a very common cause of hypotension and is very common in patients who are suffering from nausea, vomiting, or diarrhea. This shunts blood away from the organs to the muscles.
Excess Blood Loss - This quickly depletes a person's body of blood, leading to low blood pressure. This may result in trauma, surgical complications or tumors, etc.
Weakend or Dilated Heart Muscles - This causes the heart to fail and reduces the amount of blood volume it pumps out. This medical condition leads to a heart attack.
Pericarditis - In this pericardium gets inflamed. This causes the fluid to be filled within the pericardium and compresses the heart, restricting the ability of the heart to expand, fill, and pump blood.
Low Bp Symptoms
Dizziness - It is a sensation of becoming imbalance
Headache - A continuous pain in the head
Fainting - Losing consciousness for some period of time due to less amount of oxygen
Stiff Neck - A sensation of discomfort in the neck or soreness
Shortness and Shallow of Breath – Difficulty in breathing
Sweating and Fever - When someone is extremely tired
Irregular Heartbeat - Irregular beating of the heart
Diarrhea or Vomiting - Indigestion or over digestion
Fever - This is caused due to dehydration
Fatigue - Feeling overtired
Depression - A mental disorder
Nausea – A bad and uncomfortable sensation that leads to vomiting
Fun Facts
Low blood pressure is the main symptom of Addison's disease.
Hypotension is a life-threatening complication due to an infection.
Having normal blood pressure levels keeps your heart safe.
FAQs on Low Blood Pressure (Low BP) Symptoms Explained
1. What are the most common symptoms of low blood pressure (hypotension)?
The most common symptoms of low blood pressure, or hypotension, occur because the brain and other vital organs are not receiving enough blood flow. These signs include:
Dizziness or lightheadedness, especially when standing up.
Fainting (syncope).
Blurred or fading vision.
Nausea.
Fatigue and general weakness.
Cold, clammy, or pale skin.
Rapid, shallow breathing.
2. What is considered the low blood pressure (hypotension) range for an adult?
For an adult, a blood pressure reading lower than 90/60 mmHg is generally considered hypotension. The top number, systolic pressure, measures the pressure in your arteries when your heart beats. The bottom number, diastolic pressure, measures the pressure in your arteries when your heart rests between beats. A reading below 90 mmHg for systolic or 60 mmHg for diastolic pressure typically indicates low blood pressure.
3. What are the main causes of low blood pressure?
Low blood pressure can be caused by a variety of factors, ranging from lifestyle to serious medical conditions. Some primary causes include:
Dehydration: A lack of water in the body reduces blood volume.
Heart Problems: Conditions like a very low heart rate (bradycardia), heart valve problems, or heart failure can lead to hypotension.
Pregnancy: The circulatory system expands rapidly during pregnancy, which can cause a drop in blood pressure.
Endocrine Issues: Thyroid problems, adrenal insufficiency (Addison's disease), and low blood sugar can trigger hypotension.
Medications: Certain drugs, such as diuretics, beta-blockers, and some antidepressants, can lower blood pressure.
4. What happens to the body if blood pressure gets dangerously low?
When blood pressure drops to a dangerously low level, it can lead to a state of shock. In this critical condition, the blood flow to vital organs like the brain, kidneys, and heart becomes insufficient. This lack of oxygenated blood (inadequate perfusion) can cause the organs to shut down, leading to permanent damage or becoming a life-threatening medical emergency if not treated immediately. Symptoms of shock include confusion, rapid pulse, and cold skin.
5. How can someone raise their blood pressure quickly and safely during a dizzy spell?
If you feel dizzy or lightheaded due to low blood pressure, the immediate goal is to improve blood flow to the brain. Safe, quick actions include:
Sit or lie down immediately to reduce the risk of falling and injury.
Elevate your legs above the level of your heart to encourage blood flow towards the brain.
Drink a glass of water to combat potential dehydration, a common cause of low blood pressure.
Consume a small, salty snack, as sodium can help raise blood pressure.
6. Why is prolonged low blood pressure a serious health concern even without fainting?
Prolonged low blood pressure is a serious concern because it signifies chronic inadequate tissue perfusion. Even without dramatic symptoms like fainting, vital organs may consistently receive less oxygen and nutrients than they need. Over time, this can lead to subtle but significant damage. For example, the kidneys may become less efficient at filtering waste, and cognitive function may decline due to reduced blood flow to the brain. It can also indicate an underlying, undiagnosed issue like a heart or endocrine disorder.
7. How do dehydration and blood volume directly cause low blood pressure?
Blood pressure is the force exerted by circulating blood on the walls of the arteries. Your total blood volume is a key determinant of this pressure. When you are dehydrated, the fluid component of your blood (plasma) decreases, which in turn lowers your overall blood volume. With less volume of blood to pump, the pressure within the circulatory system drops, leading to hypotension. This is why rehydrating by drinking fluids is a first-line treatment for low blood pressure caused by fluid loss.
8. Are there different types of hypotension?
Yes, hypotension is classified into several types based on when the drop in blood pressure occurs. The main types include:
Orthostatic (or Postural) Hypotension: A sudden drop in blood pressure upon standing up from a sitting or lying position. It is common in older adults.
Postprandial Hypotension: This occurs 1 to 2 hours after eating, as blood flows to the digestive system.
Neurally Mediated Hypotension (NMH): This happens after standing for long periods and is caused by faulty brain signals that lower blood pressure. It is more common in children and young adults.
9. Can a blood pressure level that is 'low' for one person be normal for another?
Absolutely. What is considered low blood pressure depends on the individual's baseline. For example, highly trained athletes often have a very low resting heart rate and blood pressure (e.g., 85/55 mmHg), which is a sign of excellent cardiovascular fitness for them and causes no symptoms. However, the same reading in an elderly or typically hypertensive individual could cause severe dizziness and fainting. Therefore, low blood pressure is primarily diagnosed based on the presence of symptoms, not just the numbers alone.
