The information below is designed to help you understand what your latest blood pressure readings may mean for your health -- and to provide tips on what you can do to get or keep your blood pressure in a healthy zone.
NOTE: This information isn't a substitute for medical advice provided by your doctor. If you think you might have hypertension, elevated blood pressure, or hypotension, be sure to discuss your blood pressure concerns with a doctor or nurse, who can help you factor in other important information, such as other medical problems you may have. In particular, the information below may not always apply to those who are very old, very frail, or have multiple chronic medical conditions. View the full blood pressure chart.
Definitions of blood pressure terms
Systolic (the upper number in the reading) is the pressure in the arteries when the heart beats; it measures how hard the heart muscle is working to pump blood throughout the body.
Diastolic (the lower number in the reading) is the pressure of the blood against the blood vessel walls between heartbeats when the heart is relaxed.
What a blood pressure reading of 66/43 means
Readings below 80/60 usually indicate severely low blood pressure, which may have an underlying cause that could indicate a new, serious heart problem or infection. Very low blood pressure can also be caused by an endocrine or neurological condition. However, some people have very low blood pressure but feel fine and are otherwise healthy. Certain medications and nutritional deficiencies can worsen low blood pressure.
What to do if your blood pressure reading is 66/43
Recheck the blood pressure. Don't make a decision based on a single blood pressure reading.
If you're feeling any unusual symptoms or otherwise feel unwell, consider calling 911, especially if the very low blood pressure is new for you.
If you're on medications for blood pressure or for any other condition, they probably should be adjusted.
If you feel fine, consult your doctor and undergo tests to investigate whether there's an underlying cause that requires treatment.
Caring for those ages 80 and over
This level of blood pressure can be very concerning in an older adult. If it's new, it can signal a problem such as dehydration, infection, or internal bleeding. Low blood pressure like this can also be due to taking too much hypertension medication, or it can be a side effect of a medication prescribed for another reason.
This range of blood pressure also puts older people at risk for dizziness and falls, since blood flow to the brain tends to drop right after an older person stands up.
Don't delay in contacting a doctor regarding low blood pressure -- especially if the older person has a dementia such as Alzheimer's disease or is otherwise not able to clearly describe how he or she is feeling.
On the other hand, some diseases (such as Parkinson's disease) do cause chronic low blood pressure in older adults.
Sources: Leslie Kernisan, MD; Robert Ostfeld, MD, M.Sc., FACC; Farrokh Sohrabi, MD; Carolyn Strimike, RN, MSN