The heart is responsible for pumping blood throughout your body via a network of blood vessels. Blood pressure is the force exerted by this circulating blood against the walls of your arteries. It’s a dynamic measure, fluctuating in response to various factors like physical activity, which increases it, and hot weather, which can cause it to dip.
Hypotension, or low blood pressure, occurs when the pressure of blood circulating in your system is lower than what’s considered normal or expected under given circumstances. It’s important to understand that “low blood pressure” is relative; what’s low for one person might be perfectly healthy for another.
The critical factor is whether low blood pressure negatively impacts your health. If blood pressure drops too low for an individual, vital organs, particularly the brain, may not receive sufficient oxygen and nutrients.
Symptoms of Low Blood Pressure
A sudden, significant drop in blood pressure, often due to substantial blood loss, can lead to shock. The most alarming symptom of such acute hypotension is loss of consciousness. However, low blood pressure typically develops gradually over time.
Common symptoms of chronic low blood pressure include:
- Lightheadedness, especially when rising from a seated or lying position
- Unsteadiness or imbalance
- Dizziness or vertigo
- General weakness
- Blurred or fading vision
- Persistent fatigue or tiredness
- Fainting spells
What Causes Low Blood Pressure?
Blood pressure is measured using a sphygmomanometer. A reading that falls 30mmHg below a person’s typical blood pressure is generally classified as hypotension.
Numerous factors can contribute to low blood pressure:
- Emotional Factors: Stress, fear, insecurity, or pain are frequent triggers for fainting, leading to a temporary drop in blood pressure.
- Dehydration: Insufficient fluid intake reduces blood volume, directly lowering blood pressure.
- Heat Exposure: The body’s response to heat involves dilating blood vessels in the skin to dissipate heat. This shunting of blood to the periphery can lead to dehydration and lower blood pressure.
- Blood Donation: Donating blood temporarily reduces blood volume.
- Internal Bleeding: Conditions like a perforated stomach ulcer can cause significant internal blood loss.
- Trauma and Blood Loss: Injuries such as those from road accidents or deep cuts can result in rapid blood loss and hypotension.
- Pregnancy: Hormonal changes and circulatory system adaptations during pregnancy can sometimes lead to lower blood pressure.
- Medications for High Blood Pressure: Antihypertensive drugs are designed to lower blood pressure and can sometimes cause it to drop too low.
- Diuretics: These medications promote fluid loss through urination, which can decrease blood volume.
- Medications for Depression: Some antidepressants can have hypotension as a side effect.
- Medications for Heart Conditions: Certain heart medications can also lower blood pressure.
- Allergic Reactions: Severe allergic reactions (anaphylaxis) can cause a dramatic drop in blood pressure.
- Infections: Some severe infections, like toxic shock syndrome, can lead to hypotension.
- Heart Disease: Conditions affecting the heart’s pumping ability, such as heart failure, can result in low blood pressure.
- Nervous System Disorders: Conditions like Parkinson’s disease can disrupt the nervous system’s regulation of blood pressure.
- Addison’s Disease: This adrenal gland disorder reduces the production of hormones essential for maintaining blood pressure.
Orthostatic Hypotension: Feeling Lightheaded When Standing
Normally, when you stand up from sitting or lying down, your blood vessels constrict to counteract gravity and maintain blood pressure. Orthostatic hypotension, also known as postural hypotension, occurs when this adjustment fails. Blood pressure drops upon standing, leading to lightheadedness or dizziness.
Causes of orthostatic hypotension include:
- Nervous System Diseases: Neuropathies and other nervous system disorders can impair blood vessel response.
- Prolonged Bed Rest: Extended periods of inactivity can weaken the body’s ability to regulate blood pressure upon standing.
- Dehydration: Reduced blood volume exacerbates the drop in blood pressure when standing.
- Irregular Heartbeat (Arrhythmia): Heart rhythm abnormalities can affect blood pressure regulation.
Treatment for Low Blood Pressure
Treatment for hypotension is tailored to the underlying cause. For instance, if medications are the culprit, adjusting dosages may be necessary. A bleeding stomach ulcer would require surgical intervention. In cases where no specific cause is identified, medications to raise blood pressure might be prescribed. In extreme situations, a lower body pressure suit, which helps maintain blood pressure, may be needed.
Where to Seek Help
If you are experiencing persistent symptoms of low blood pressure, it is important to consult your doctor for diagnosis and appropriate management.
Key Takeaways
- Hypotension, or low blood pressure, means that the pressure of blood circulating in the body is lower than what is considered normal.
- Low blood pressure becomes a concern when it causes negative effects on the body and produces noticeable symptoms.
- Various factors can cause hypotension, including blood loss, dehydration, and certain medications, particularly those for high blood pressure.
