Blood pressure is a measurement of the force your blood exerts against the walls of your arteries as your heart pumps it through your body. It is typically expressed as two numbers. The first number, systolic pressure, measures the pressure in your arteries when your heart beats and contracts. The second number, diastolic pressure, measures the pressure in your arteries when your heart rests between beats.
What is Low Diastolic Pressure?
A blood pressure reading is considered low when the diastolic number falls below a certain threshold. A reading consistently below 60 mmHg is generally considered low. This condition is sometimes referred to as isolated diastolic hypotension when only the diastolic reading is low, while the systolic pressure remains normal or even high. A single low reading might not indicate a problem, as blood pressure naturally fluctuates. Persistent low diastolic readings, especially with symptoms, warrant further investigation.
Why Diastolic Pressure Can Be Low
Several factors and underlying conditions can contribute to a low diastolic blood pressure reading. Certain medications are a common cause, including diuretics and other blood pressure drugs. Alpha-blockers, prescribed for high blood pressure or an enlarged prostate, can reduce diastolic pressure. Dehydration from insufficient fluid intake, vomiting, or severe diarrhea diminishes blood volume, lowering blood pressure.
Aortic regurgitation, where the aortic valve does not close properly, allows blood to leak back into the heart, causing low diastolic pressure. Heart failure or a slow heart rate (bradycardia) can impair the heart’s pumping ability, affecting overall blood pressure. Severe infections, such as sepsis, can cause widespread vasodilation (widening of blood vessels), leading to a significant drop in both systolic and diastolic pressures. Endocrine problems, including Addison’s disease (adrenal insufficiency), and significant blood loss from injury or internal bleeding, reduce blood volume, directly impacting blood pressure. Aging can also contribute, as arteries may become stiffer, sometimes leading to a higher systolic and lower diastolic pressure.
Signs and When to Act
Low diastolic pressure can manifest through various symptoms. Individuals may experience dizziness or lightheadedness, particularly when standing up quickly. Fainting (syncope) can occur if the brain does not receive sufficient blood flow. Blurred vision, fatigue, and nausea are also potential indicators. In more severe cases, confusion or difficulty concentrating might arise.
Seek medical attention if low diastolic readings are persistent or if symptoms are present. If you experience recurrent dizziness, fainting spells, or significant fatigue, consult a healthcare professional. A sudden, unexplained drop in blood pressure, especially with severe symptoms, requires immediate medical evaluation. Regular home blood pressure monitoring can help identify patterns and provide valuable information for your doctor.
What to Do About Low Diastolic Pressure
Addressing low diastolic pressure involves identifying and managing the underlying cause, often with a medical professional. Lifestyle adjustments can help improve blood pressure readings. Increasing fluid intake, especially water, helps maintain adequate blood volume. Dietary changes, such as a balanced diet and, if advised by a doctor, adjusting sodium intake, can also be beneficial. Avoiding sudden changes in position, such as slowly rising from a lying or sitting position, can help prevent dizziness and falls associated with orthostatic hypotension.
If medication is the cause, a doctor may adjust dosages or explore alternative treatments, but only under medical supervision. For underlying medical conditions like heart issues, infections, or endocrine disorders, treating the primary condition is paramount. Managing heart failure or addressing an infection will likely help normalize blood pressure. Always consult a healthcare professional for an accurate diagnosis and a personalized treatment plan.