Mayo Clinic: What is considered "low" for the
diastolic number in a blood pressure reading? What would a low
reading mean? If the systolic number is within normal range,
what can be done to alter the diastolic number?
blood pressure reading has two numbers, given in millimeters
of mercury. The first, or upper, number measures the pressure
in your arteries when your heart beats. Thatís systolic
pressure. The second, or lower, number measures the pressure
in your arteries between beats. Thatís the diastolic
general, diastolic blood pressure is considered to be low if
it is 60 millimeters of mercury or less. Normal blood pressure
varies from one person to another though. If your diastolic
blood pressure is consistently below 60 millimeters of
mercury, but you arenít experiencing any problems from it,
you may not need to do anything. Noticeable symptoms of low
blood pressure generally include dizziness, lightheadedness or
fainting. If youíre having these or other symptoms that
could be related to low blood pressure, more investigation may
be required to uncover the possible cause and provide
cases, medications can cause low diastolic blood pressure. In
particular, medications intended to lower blood pressure,
called anti-hypertensives, may go too far in the other
direction, reducing blood pressure beyond a healthy level.
These anti-hypertensives include diuretics (sometimes called
water pills), alpha blockers and beta blockers. Other
medications also may lead to low blood pressure, such as drugs
for Parkinsonís disease, certain types of antidepressants,
and the drug sildenafil, particularly in combination with
heart medication (e.g., nitroglycerine).
underlying medical condition could trigger low blood pressure,
as well. For example, heart problems, such as extremely low
heart rate, heart valve problems and heart failure, may cause
low blood pressure, because they prevent the body from being
able to circulate enough blood. Endocrine disorders, such as
adrenal insufficiency, also can trigger low blood pressure.
conditions, including dehydration, blood loss, severe
infection and a severe allergic reaction, can lead to low
blood pressure. But, these disorders usually cause a sudden,
dramatic drop in pressure, rather than a sustained low blood
pressure reading over time.
possible cause for low diastolic blood pressure is extremely
stiff arteries. Very often, around 55 to 60 years of age,
arteries begin to lose some of their flexibility. That can
increase systolic blood pressure and cause discordantly low
diastolic blood pressure. In some cases, however, stiff
arteries could be a symptom of vascular disease.
your diastolic blood pressure is consistently below normal, it
may need to be evaluated. In young healthy people who do not
take medications or have any symptoms, no treatment may be
needed. But, itís still a good idea to talk to your doctor
about it. If you do take medications, ask your doctor to
review your current medication list to see if they could be
contributing to low blood pressure.
doctor suspects that an underlying disorder could be the
source of the problem, then additional tests may be necessary.
It also would be worthwhile to talk with your doctor about
managing any vascular risk factors you may have that can be
changed, such as smoking, high cholesterol, diabetes and
obesity. When a medical condition leads to low diastolic blood
pressure, successfully treating that problem may eliminate the
low blood pressure, too.