Hypotension

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Hypotension can cause dizziness, blurred vision and even confusion. Talking to one of our health care professionals at Atrium Health Floyd and Harbin Clinic can help you understand the cause of your hypotension and figure out if it’s something that needs to be managed to ensure your best health.

What is hypotension?

If you have hypotension, it means you have lower than average blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries. Each time the heart beats, it pumps out blood into the arteries.

Blood pressure is highest when the heart beats, pumping the blood. This is called systolic pressure. When the heart is at rest, between beats, blood pressure falls. This is the diastolic pressure.

Blood pressure reading uses these two numbers written one above the other, such as 120/80 mm Hg. Here, mm Hg means millimeters of mercury. If a blood pressure reading is 90/60 mm Hg or lower, it is considered low blood pressure.

Some people have low blood pressure all the time. They have no symptoms and their low readings are normal for them. In other people, blood pressure drops below normal because of a medical condition or medicine they’re taking.

Some people may have symptoms of low blood pressure when standing up too quickly. Low blood pressure is a problem only if it causes dizziness, fainting or in extreme cases, shock.

Types of hypotension

Hypotension can be caused by a variety of factors and, as such, there are several different types.

Orthostatic hypotension occurs when blood pressure drops after standing, causing dizziness or lightheadedness.
Absolute hypotension is a resting blood pressure below 90/60 mm Hg.
Post-prandial hypotension occurs after eating, specifically in older adults and those with autonomic dysfunction.
Hypotensive shock includes cardiogenic shock, which occurs following heart failure or heart attacks; hypovolemic shock, which occurs following severe dehydration or a drop in blood volume; distributive shock, which occurs when states like septic shock cause widening of the blood vessels; and obstructive shock, which follows a pulmonary embolism or cardiac tamponade.

Other types of hypotension occur due to allergic reactions causing a drop in blood pressure (anaphylactic shock), spinal cord injuries (neurogenic shock) or a dysregulated autonomic nervous system (neurally mediated hypotension).

What causes hypotension?

Conditions or factors that disrupt the body’s ability to control blood pressure cause hypotension. The different types of hypotension have different causes.

Orthostatic hypotension causes

Orthostatic hypotension has many causes. Dehydration is the most common and can be brought on by not drinking enough fluids, sweating a lot during physical activity, fever, vomiting or severe diarrhea. It may occur during pregnancy but usually goes away after birth.

The risk of developing orthostatic hypotension increases if you have:

Anemia
Endocrine conditions like Addison’s disease, diabetes, or thyroid disorders
Heart attack, heart failure or other conditions like heart valve disease
Parkinson’s disease and other central nervous system disorders
Pulmonary embolism
Severe infections

Postprandial hypotension causes

Postprandial hypotension is a sudden drop in blood pressure after a meal. It mostly affects older adults because an older body doesn’t manage changes in blood pressure as well as a younger body.

Neurally mediated hypotension causes

Neurally mediated hypotension occurs when the brain and heart don’t communicate with each other properly. Standing for a long time is one example of something that can cause the body to mistakenly believe its blood pressure is too high. In response, the brain slows the heart rate. This makes blood pressure drop even more, causing dizziness and other symptoms.

Shock-related hypotension causes

Shock may cause blood pressure to drop and not return to normal on its own. The early signs and symptoms of reduced blood flow to the brain include light-headedness, sleepiness and confusion.

In the earliest stages of shock, it may be hard to detect any signs or symptoms. In older people, the first symptom may only be confusion. Over time, as shock worsens, a person won’t be able to sit up without passing out. If the shock continues, the person will lose consciousness. Shock often is fatal if not treated right away.

Shock is an emergency and must be treated right away. If a person has signs or symptoms of shock, call 911.

Other causes of hypotension

Other causes of hypotension include:

Addison’s disease
Alcohol or barbiturates
Anemia
Blood loss
Dehydration
Extremely low heart rate (bradycardia)
Heart attack or heart failure
Heart valve disease
Liver failure
Low blood sugar or diabetes
Parkinson’s disease
Poisoning
Pulmonary embolism
Septic shock
Severe allergic reaction or anaphylactic shock
Severe infections
Some prescription or over-the-counter medication
Thyroid disorders

What are the symptoms of hypotension?

The signs and symptoms of hypotension include:

Blurry vision
Confusion
Dizziness or light-headedness
Fatigue
Nausea
Weakness

Hypotension diagnosis

Your doctor will conduct a physical exam, ask about your medical history and check your blood pressure to diagnose hypotension.

Hypotension risk factors

Hypotension can affect people of all ages. However, people in certain age groups are more likely to have certain types of hypotension.

Older adults are more likely to have orthostatic and postprandial hypotension. Children and young adults are more likely to have neurally mediated hypotension.

People who take diuretics or high blood pressure medication are also at increased risk for hypotension.

Other risk factors for hypotension include being immobile or not able to move around very much for long periods, being out in the heat for a long time and pregnancy.

Hypotension treatment & recovery

Treatment depends on the type of hypotension and the severity of the symptoms. The response to treatment depends on age, overall health and strength. It also depends on how easily medicines can be stopped, started or changed. In a healthy person, low blood pressure without signs or symptoms usually isn’t a problem and needs no treatment.