
Blood pressure represents the pressure of blood in the walls of blood vessels. Blood pressure that is too high damages blood vessels and organ systems. Low blood pressure causes a decrease in the blood supply to the organs in the body. Sudden drop in blood pressure (also called hypotension) can cause many dangerous complications. Let’s learn about low blood pressure to have the right attitude through the article of Doctor Luong Sy Bac!
What is low blood pressure?
Low blood pressure also known as hypotension is a sudden drop in blood pressure below 90/60 mmHg. That is, the systolic blood pressure is less than 90 mmHg and/or the diastolic blood pressure is less than 60 mmHg. Low blood pressure has many causes with varying degrees of danger. However, most of the causes hypotension all affect health. In particular, in certain groups of patients, hypotension can cause serious irreversible damage such as: patients with cardiovascular disease, kidney disease, family members, severe infections…

Low blood pressure is a dangerous condition
Causes of low blood pressure
There are many possible causes of a sudden drop in blood pressure. They can be roughly classified into the following groups:
Related to medical conditions
Medical conditions that can hypotension to be:
Heart-related diseaes
This is a group of dangerous causes. Heart failure, myocardial infarction, arrhythmia, heart valve disease… can all cause a sudden drop in blood pressure. When there is underlying cardiovascular disease, hypotension always have serious meaning. A positive approach is required to ensure patient safety.
Endocrine disease
Endocrine diseases directly affect blood pressure by regulating the body’s activities through hormones. The most common are hypothyroidism – parathyroid, adrenal insufficiency. Some cases of diabetes also cause a drop in blood pressure. Hypotension in this group of patients is also often an emergency and requires hospitalization for follow-up.
Dehydration
Water is the main structural component of blood in particular and the body in general. Physiologically, the body has response mechanisms to ensure stable blood pressure when dehydrated. However, if you lose a lot of water, it can be acute hypotension. Common causes of dehydration are: fever, vomiting, acute diarrhea, abuse of diuretics… Dehydration can cause dehydration. hypotension need to be hospitalized for immediate rehydration. If it is quick and timely, a full recovery can be achieved.
Bleed
Bleeding reduces blood flow causing hypotension. The most common is major trauma that causes blood loss. In addition, severe blood loss can also be seen in obstetric hemorrhage, rupture of large blood vessels, perforation or rupture of large organs in the body… This group of diseases needs urgent blood transfusion to avoid irreversible organ damage. . Each person should know his or her blood type, so that emergency care can be given in time.

Aneurysm rupture is the cause of severe blood loss
Severe infection
Septic shock is a common cause of death in patients with severe infections. Hypotension in septic shock is due to redistribution of body fluids. That is, water remains in the body but is drawn out of the blood vessels. Thereby reducing the supply to the organs, causing multi-organ damage. Septic shock requires antibiotic therapy and adequate fluid resuscitation.
Anaphylactic reaction
Anaphylaxis is a common emergency. Anaphylaxis is caused by an allergy to a specific agent. Common triggers of severe allergic reactions are foods, certain medications, insect venoms, etc. People with anaphylaxis often have difficulty breathing, an allergic rash, and itching. hypotension… It is necessary to immediately bring the patient to the nearest medical facility for timely emergency treatment.

Signs of an anaphylactic reaction
Drug-induced drop in blood pressure
Certain medications can cause low blood pressure, including:
- Diuretic.
- Medicines to treat high blood pressure. An overdose of antihypertensive drugs can cause hypotension.
- Drugs for the treatment of cardiovascular disease.
- Drugs to treat Parkinson’s disease. The most common is levodopa and pramipexole-induced hypotension.
- Certain antidepressants.
- Medicines for erectile dysfunction. Common in the sildenafil group (Revatio, Viagra) or Tadalafil. Drugs can cause hypotension strong if combined with vasodilators (treatment of cardiovascular disease, blood pressure).
Other hypotensive conditions
Postural hypotension
- This is a sudden drop in blood pressure when changing positions. It can be standing up suddenly from a sitting position or sitting up from a lying position… When you stand up suddenly, the blood under gravity accumulates in the legs, which temporarily reduces blood flow to the heart. Normally, the body compensates by increasing heart rate and constricting blood vessels, thus ensuring cardiac preload. But in people with orthostatic hypotension, this compensatory mechanism fails to compensate and blood pressure drops.
- The consequences can lead to dizziness, lightheadedness, blurred vision, and even fainting.
- Orthostatic hypotension has many different causes. Common include dehydration, prolonged bed rest, pregnancy, diabetes, heart disease, burns, extreme heat, large varicose veins, and certain neurological disorders.
- Some medications can also cause orthostatic hypotension. Especially drugs used to treat high blood pressure, antidepressants, drugs for Parkinson’s and erectile dysfunction. Orthostatic hypotension is particularly common in the elderly population.

Orthostatic hypotension increases the risk of falls in the elderly
Low blood pressure after meals
This drop in blood pressure occurs one to two hours after eating and occurs mainly in the elderly. Caused by blood pooling in the digestive system, causing a temporary shortage. Symptoms are often obvious in elderly patients, with low baseline blood pressure… Splitting meals, reducing carbohydrates, drinking plenty of water, and avoiding alcohol can help reduce symptoms.
Low blood pressure due to brain signals
Or nerve-mediated hypotension. This disorder does hypotension after standing for a long time. Most affect adults and children. The mechanism seems to occur due to miscommunication between the heart and the brain.
Low blood pressure due to damage to the nervous system
Damage to the autonomic nervous system disrupts blood pressure regulation.
Signs of low blood pressure
Symptoms of hypotension Depending on the severity, the cause of low blood pressure… It is important to note the following signs:
- Dizziness, headache, lightheadedness, dizziness.
- Faint.
- Lack of focus.
- Blurred eyes.
- Nausea, vomiting.
- Tired.
- Excited, fast heart beat.
- Chest pain, difficulty breathing.
Chronic hypotension is usually asymptomatic. Hypotension Acute with the above signs requires immediate emergency care.

Signs of low blood pressure
How is low blood pressure diagnosed and treated?
Diagnosing low blood pressure
In emergency cases, when there are suspicious signs, it is necessary to immediately measure blood pressure to confirm. Once hypotension has been identified, the cause of the hypotension must be investigated. Diagnosis of etiology must be based on the patient’s history, symptoms, physical examination, and laboratory tests. The total combination of new factors can provide an accurate diagnosis. The problem is very diverse, complex and needs to be done in the hospital. The role of the patient and family is to notice and detect in time.
For cases of occult orthostatic hypotension, blood pressure can be measured when changing positions. Or you can do the tilt table test. =

Tilt table test for diagnosis of orthostatic hypotension
Treatment of low blood pressure
The priority is to stabilize the patient’s blood pressure. Depending on the condition, the patient can be rehydrated, blood transfusion. In severe cases, vasopressors and intravenous heart support may be required.
Once the blood pressure is stable, treatment depends on the cause of the disease. Treat each specific etiology refer to the articles on each etiology.
Sudden drop in blood pressure should do?
When there are signs hypotension First of all, you need to stay calm. First aid also plays an important role in limiting complications. A few things to keep in mind:
- Lay the patient down slowly in a flat, low-head position.
- If the patient is awake, the patient can be given a small amount of water to drink. If there are signs of decreased consciousness, absolutely do not eat or drink anything.
- Immediately contact the nearest medical facility for timely emergency treatment.
- Check the patient’s medication, food, and condition to report back to the doctor.
For cases of orthostatic hypotension or chronic hypotension, when resting, blood pressure will usually stabilize. However, it is still necessary to monitor and consult a doctor to be able to overcome the above situation.
Measures to prevent low blood pressure
Some preventive measures hypotension may apply:
- Use more salt. Increasing salt in the diet can raise blood pressure. However, too much salt is harmful to health. Eat the right amount.
- Drink more water. Drink enough water on average from 2 to 2.5 liters per day. Drinking coffee also contributes to high blood pressure.
- Wear pressure socks. Medical stockings improve blood flow from the legs to the heart.
Low blood pressure is a dangerous condition that can have serious health consequences. It is necessary to monitor for timely detection and intervention, especially in at-risk patient groups. Timely emergency care can limit complications and protect the patient’s health. Hopefully, Doctor Luong Sy Bac’s article can provide you with useful information!

John Alen was born in 1971 and is a doctor in the healthcare and psychology fields with many years of experience. He is currently working at easyhealthylive.com, a leading health and psychology blog. Having studied at Y1 National Medical University named after IM Sechenov, John Alen is using his knowledge and experience to help improve the physical and mental health of people in the United States.