Understanding Hypotension
A blood pressure reading contains two numbers: systolic pressure and diastolic pressure. Systolic pressure is the top, or first, number in your blood pressure reading; it indicates the pressure within your arteries when your heart pumps out blood. Diastolic pressure is the bottom number, showing the pressure in your arteries while your heart is filling with blood. If your blood pressure is 120/80 millimeters of mercury (mm Hg) or lower, it’s considered normal. Generally, if the blood pressure reading is under 90/60 mm Hg, it is abnormally low and is referred to as hypotension. Some adults regularly have blood pressure in the hypotensive range but have no symptoms and do not require treatment. In serious cases, though, hypotension can result in a decreased supply of oxygen and nutrients to your brain and other essential organs, which can eventually lead to life-threatening shock.
DizzinessFaintingFatigueProblems concentratingBlurry visionNauseaClammy, pale skinShortness of breath
What Is a Dangerously Low Blood Pressure Number?
According to the AHA, there is no specific number at which day-to-day blood pressure is considered too low. However, when low blood pressure is accompanied by any of the above listed dangerous symptoms, it is time to seek medical care.
When Low Blood Pressure Can Strike
Some people have naturally low blood pressure, and they don’t experience any symptoms. But for those who are used to having high blood pressure, a sudden decrease in blood pressure can signal a problem and can cause the symptoms listed above. An episode of hypotension is more likely to occur under these conditions:
Resuming an upright posture after bed rest for a long period of timeBeing in the first 24 weeks of pregnancyLosing a large amount of bloodBeing dehydratedTaking certain medications, such as blood-pressure-lowering medications, heart medications, Parkinson’s disease medications, tricyclic antidepressants, or medications to treat erectile dysfunctionHaving a heart problem, such as a very slow heartbeat, heart valve problems, heart attack, or heart failureHaving a endocrine problem, such as hypothyroidism, parathyroid disease, Addison’s disease (an adrenal gland disorder), low blood sugar, or diabetesHaving a severe infection that enters your bloodstreamExperiencing anaphylaxis, a life-threatening allergic reactionHaving a neural disorder that affects your blood pressureHaving a nutrient deficiency, such as low vitamin B12 and folic acid levels
Can Low Blood Pressure Make You Tired?
Low blood pressure can cause fatigue — that feeling of overwhelming tiredness and lack of energy. Research has found an association between low blood pressure and chronic fatigue syndrome, a condition characterized by profound fatigue, pain, and sleep abnormalities that are often made worse by exertion. There is no cure for this type of fatigue, but doctors may suggest treating underlying causes, such as sleep disorders or mental health issues. Treating low blood pressure with dietary changes and proper physical activity can also help.
When Do You Need Medical Care for Hypotension?
If your blood pressure is always on the low side and you do not have any of the dangerous symptoms, there is usually no cause for concern. Similarly, if you have a single at-home blood pressure reading that is abnormally low without any symptoms, you probably do not need to see your doctor. It is normal for your blood pressure to rise and fall over time, and your body is usually able to get your blood pressure back to normal. But, says Dr. Lawrence, “when you sense there’s a recurrent problem, or there’s no clear explanation for what’s happened, you need to seek medical advice." If your blood pressure drops suddenly and you are experiencing symptoms like dizziness, you should call your healthcare provider. They can assess your situation and rule out underlying problems, such as internal bleeding, serious infection, or an allergic reaction. Treatment for hypotension will depend on the cause of the low blood pressure. Immediate steps might include the following:
Lying with your feet above your heartDrinking fluidsAvoiding hypotension triggers like prolonged standing
After evaluation, a doctor may make these recommendations:
Avoid alcohol.Adjust your diet.Adjust your medications (possibly lowering dosages of blood-pressure-lowering drugs).Take blood-pressure-raising medications, such as Florinef (fludrocortisone) and ProAmatine (midodrine).Weare compression stockings.
People who experience shock related to hypotension will need emergency treatment to restore blood flow to their organs and raise their blood pressure back to normal. It’s important to determine whether your low blood pressure is “a primary problem or secondary problem,” notes Lawrence. A primary problem means that the body’s reflexes are not working as they should. Secondary causes mean that the low blood pressure is a result of things like dehydration or the effects of certain medications. “Some antihypertensive [medications] are more likely to cause hypotension than others, and a lot of it is dose-dependent,” says Lawrence. “In most people, there will be some easily identifiable secondary cause or some easy solution to what may even be a chronic problem that has no secondary cause, and that’s why it’s important to see your doctor, so they can make an appropriate assessment.” Keep track of your blood pressure readings, even if you don’t have any health issues, so that you know what your personal normal reading is. And if your blood pressure is being monitored, talk to your doctor about the blood pressure target range that’s best for you. Additional reporting by Ashley Welch.
