1. Definition
Hypotension is a condition characterized by abnormally low blood pressure, typically defined as a systolic pressure below 90 mmHg and/or a diastolic pressure below 60 mmHg. It can result in inadequate blood flow to vital organs, causing symptoms such as dizziness, fainting, or shock in severe cases.
2. Calculation
There is no formula to «calculate» hypotension, as it is determined by measuring blood pressure using a blood pressure monitor.
3. Influencing factor
- Dehydration
- Heart problems: Weak heart function or heart valve issues can lead to low blood pressure.
- Endocrine problems: Hormonal imbalances, like underactive thyroid (hypothyroidism) or adrenal insufficiency
- Blood loss: Severe injury or internal bleeding.
- Infections: Severe infections (like sepsis) can cause a drastic drop in blood pressure.
- Medications: Certain medications like diuretics, beta-blockers, or antidepressants can lower blood pressure.
- Nutritional deficiencies: Lack of essential vitamins like B12 and folic acid can cause hypotension by affecting red blood cell production.
- Pregnancy: Blood pressure naturally decreases during the first and second trimesters of pregnancy.
- Severe allergic reactions: Anaphylaxis can cause a sudden and dangerous drop in blood pressure.
- Prolonged bed rest: Being immobile for extended periods can reduce blood pressure due to decreased circulation.
- Standing up quickly: Known as orthostatic hypotension, standing up too fast can cause a sudden drop in blood pressure.
- Extreme temperatures: Hot environments can cause blood vessels to widen, lowering blood pressure.
4. Classfication
4. 1 Idiopathic Hypotension (Primary Hypotension)
Low blood pressure with no identifiable underlying cause.
Characteristics
- Often considered a benign condition, particularly if there are no symptoms.
- Some individuals naturally have low blood pressure, which may be normal for them.
- Common in young, healthy individuals and may not require treatment if it doesn’t cause symptoms.
Symptoms: If symptoms do occur, they may include dizziness, fatigue, or fainting.
4.2 Secondary Hypotension:
Low blood pressure caused by an underlying medical condition or external factor.
- Characteristics:
- Secondary to diseases such as heart problems, dehydration, endocrine issues (e.g., adrenal insufficiency, hypothyroidism), or severe infections.
- Can also be caused by medications (e.g., diuretics, beta-blockers) or excessive blood loss.
- Treating the underlying cause often resolves the low blood pressure.
- Examples:
- Heart failure: Weak heart pumping can lead to low blood pressure.
- Endocrine disorders: Hormonal imbalances can affect blood pressure regulation.
- Medications: Certain drugs can lead to hypotension as a side effect