It’s not uncommon to get dizzy when you stand from a seated or lying position. Some people call it a “head rush.” The medical name for it is orthostatic hypotension or postural hypotension.
It can happen to anyone, but feeling lightheaded when you stand is more likely to occur as you age. Up to 20% of people over age 65 experience some degree of orthostatic hypotension.
That woozy rush may feel like a fleeting concern. But if it happens frequently or the dizziness persists for more than 15 seconds, you are putting yourself at increased risk for falls and injury. You may also have an underlying issue.
What is orthostatic hypotension?
Orthostatic hypotension is a sudden drop in blood pressure when you stand. It happens because your blood moves away from your heart and brain and pools in your legs. Sometimes, the process of pumping blood back up to your heart occurs incorrectly or too slowly, giving you that lightheaded feeling.
Of note: If you are only dizzy when you stand after a meal, it may be due to a different condition called postprandial hypotension. Postprandial hypotension is also a drop in blood pressure, but experts think it’s related to blood being diverted to the digestive system.
To be clinically diagnosed with orthostatic hypotension, your blood pressure must show one of the following changes within three minutes of standing up:
- Systolic blood pressure: The top number — measuring the force of blood your heart pumps out — decreases by at least 20 millimeters of mercury (mmHg).
- Diastolic pressure: The bottom number — measuring the force of blood as your heart refills between beats — decreases by 10 mmHg.
Symptoms of orthostatic hypotension typically go away if you lay down. These may include:
- Blurred vision
- Chest pain or trouble breathing
- Nausea
- Weakness
Reasons you might get dizzy when you stand up
Frequently feeling lightheaded upon standing may be a symptom of an underlying problem. However, if it only happens occasionally, it may be caused by something that is easy to correct.
Common causes of orthostatic hypotension include:
Dehydration
Many people experience dizziness upon standing mostly in the morning. One reason for that is that dehydration can trigger orthostatic hypotension.
Your blood is mostly water. When you are dehydrated — which can happen overnight — your total blood volume decreases and can lower your blood pressure.
Dehydration can also happen if you are vomiting, sweating or have diarrhea. Drink fluids throughout the day to stay hydrated overnight.
Endocrine disorders
Endocrine disorders can cause hormonal imbalances. An imbalance with the hormones that affect blood pressure or heart function may cause orthostatic hypotension.
Endocrine disorders that commonly cause you to feel dizzy when you stand up include:
- Addison’s disease (adrenal insufficiency)
- Diabetes
- Hypoglycemia (low blood sugar)
- Thyroid conditions
Heart problems
There is a strong association between cardiovascular disease and orthostatic hypotension, and risks for both increase with age. Cardiovascular disease increases your risk for orthostatic hypotension, and conversely, orthostatic hypotension may increase your risk of heart disease.
Heart conditions most likely to cause orthostatic hypotension include:
- Arrhythmias (irregular heartbeat)
- Atherosclerosis (hardening of the arteries)
- Heart failure
- Heart valve disease
- Hypertension (high blood pressure)
Medications
Many drugs can lower blood pressure, leaving you more likely to experience dizziness. Common culprits include medications for:
- Chest pain
- Depression and other mental health conditions
- Erectile dysfunction
- High blood pressure
Your pharmacist or primary care physician can tell you whether low blood pressure is a side effect of your medication.
Neurodegenerative conditions
Some neurodegenerative conditions, such as Parkinson’s disease and dementia, can disrupt the body’s ability to control blood pressure.
Research also shows that orthostatic hypotension may increase your risk of developing dementia. One study found that people whose systolic blood pressure decreased by 20 mmHg or more in the first 30 seconds of standing were 22% more likely to develop dementia than people whose blood pressure remained stable.
How to prevent dizziness upon standing
If you notice yourself getting lightheaded when you stand up, pay attention to when it happens. If your dizziness is mild or occasional, there are steps that may help reduce the occurrence and severity:
- Check your medications to see if dizziness is a common side effect
- Eat smaller, more frequent meals if dizziness happens after eating
- Get up slowly to give your body time to adjust
- Hydrate throughout the day
- Squeeze your leg muscles as you stand to keep blood moving
When to see a health care professional
If your dizzy spells are infrequent and last less than 15 seconds, you may be slightly dehydrated. If you are dizzy often or the feeling lasts longer than 15 seconds, you should contact your primary care physician.
Your provider will check your blood pressure as you lie down, sit and stand. They will also conduct a physical exam and review your medical history and medications. They can refer you to a heart or nervous system specialist if needed.
