What causes dizziness and lightheadedness when you stand up

It’s common to feel light-headed when you stand too quickly from lying down or sitting, and after exercise. Fainting or dizzy spells can occur from a simple shift in body positioning that pulls your bloodflow downwards.

“It’s called orthostatic hypotension or postural hypotension and it’s essentially a form of low blood pressure,” says exercise physiologist Michael Crawford. 

What happens when I feel dizzy?

In its acute (or short-lived) form, dizziness occurs from lying or sitting for long periods of time and then standing quickly, or when you’re dehydrated — like when you’re sick or when you exercise. There can be other underlying triggers for dizziness, but during exercise a quick change in the exercise position, difficulty or suddenly stop may result in low blood pressure causing dizziness.

With some forms of exercise you may be shifting the areas where your blood flows. Simply standing from a lying or seated position (more often during exercise) makes blood rush and gather down in your legs and abdomen. This means less blood is circulating and getting back to your heart, causing the decrease in your blood pressure. 

Cells called baroreceptors near your heart and neck detect this low blood pressure and send signals to your brain. Once your brain hears the news it tells your heart to pump faster to pump more blood in order to get your blood pressure back to normal. Until your blood pressure returns to normal, you may feel lightheaded.

Dehydration during exercise can also cause dizziness

Dehydration is known to decrease your blood volume and can also make you feel lightheaded as your brain sends messages to your heart to stabilize your blood pressure. Exercises that produce higher amounts of sweat are more likely to result in dehydration. 

When dizziness is a result of inactivity

Dizziness can also be a sign of postural orthostatic tachycardia syndrome (POTS). This condition most frequently affects young women who may struggle to stay active. People with POTS who exercise can feel dizzy or even pass out.

But there are ways to help offset these challenges. Crawford emphasizes it’s important to find ways to exercise because it increases blood volume, the size and strength of the heart and its pumping action.

“Most people I work with see some sort of improvement with exercise — they may still have symptoms but they occur less frequently,” he says.

The important thing is to follow all of your treatment strategies if you have POTS. This includes taking your medication, increasing fluids, wearing compression stockings and gradually increasing physical activity over time.

Best and worst exercises to do for POTS

Newer research suggests that aerobic exercises that are not as gravitationally challenging are best for people with POTS. 

The ultimate goal is to progress over time to fully upright exercises so you can manage symptoms. Staying in a semi-recumbent position doesn’t do that.

“You can use semi-recumbent cycling, rowing machines and a seated stair-stepper to decrease the risk of syncope (passing out),” Crawford says. If weightlifting, work the lower body in seated positions with a leg press or seated abdominal exercises. Strengthening the lower body reduces blood pooling in the legs.

For the first three to four weeks try a semi-recumbent work at a moderate intensity level. You can gradually increase that intensity then progress to something more upright like a stationary cycle for another 3 or 4 weeks. 

“If that works well I transition people to a treadmill or elliptical machine. You’ll need to make sure you aren’t working too intensely. Once you’re feeling better, you can begin to work out normally,” he says. He suggests you stay away from free weights because a dizzy spell can increase chances you might drop the weight. Also, avoid high-intensity work or exercises with a rapid change in position.

How often to exercise with POTS 

Here is how people with POTS can build up their workout schedule:

• Start out working three days a week, resting between days.
• Add in a fourth day after about three weeks.
• After a few more weeks you can add a fifth day.

“Go for 20 minutes a day and add five minutes to that every two to three weeks. Eventually you can exercise 40 to 45 minutes most days in line with what’s recommended for everyone,” Mr. Crawford says. And remember these tips:

• Hydrate, hydrate, hydrate — You need to prehydrate 30 minutes before you go to the gym with about 8 ounces of fluid. Drink water unless your doctor encourages you to have a sports drink. For every 15 minutes of exercise drink 4 ounces of fluid.
• Don’t skimp on warm ups and cool downs — People with POTS need to warm up and cool down very slowly for five minutes each. “For the warm up be sure to progressively increase your exercise over the first five minutes until you get to your conditioning phase. For cool down steadily decrease your exercise over five minutes before you stop,” Crawford says.
• Watch your target heart rate — Be sure you’re staying in your target heart rate where you feel comfortable. POTS patients don’t fall into typical exercise heart-rate levels so testing determines what they can tolerate. Know your parameters and stay within those levels.

“If you need help getting into exercise, start with getting an evaluation from a cardiologist or neurologist to make sure there aren’t underlying issues causing the condition,” Crawford says. “Once that’s sorted out, you should see an exercise physiologist who knows about POTS.”

Other medical conditions that cause dizziness

Not drinking enough fluids, fever, vomiting or severe diarrhea can also cause dehydration and dizziness.

And some medical conditions can prevent your body from responding rapidly enough to pump more blood when standing up such as:

• Extremely low heart rate (bradycardia).
• Heart valve problems.
• Heart attack or heart failure. 

There are also several nervous system disorders can disrupt your body’s normal blood pressure regulation system such as:

• Parkinson’s disease.
• Multiple system atrophy.
• Pure autonomic failure.

Endocrine problems that can cause dizziness:

• Low blood sugar (hypoglycemia).
• Diabetes (which can damage nerves that regulate blood pressure).
• Thyroid conditions.
• Adrenal insufficiency (Addison’s disease).

“In general, orthostatic hypotension can range from a few seconds to several minutes, but if it happens frequently it can be a flag for more serious medical conditions,” Crawford emphasizes. “See your doctor if you feel light-headed when standing up on a regular basis.” 

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If you’ve ever had that feeling of dizziness when standing up too fast, you may wonder what’s going on. 

Depending on the cause, it may not be a long-term problem. But if you feel faint or actually lose consciousness, talk to your doctor as soon as possible.

“The feeling that you’re about to faint is called ‘presyncope,’” says Lia F. Crispell, certified registered nurse practitioner at ConvenientCare in Wilkes-Barre. “It happens when the brain doesn’t get enough blood, oxygen or glucose to function properly, even momentarily.”

The common causes of lightheadedness

People who experience presyncope usually dismiss it and move on with their day. “This isn’t a good idea since some of the causes can be serious. It’s always best to get a diagnosis from a doctor,” says Crispell. Especially because dizziness can be a symptom of an underlying medical condition.

Potential causes of presyncope include:

Orthostatic hypotension

Also called postural hypotension, this is the head rush you sometimes feel when you stand up. It can happen to anyone — and it tends to happen more often if you’re taking certain medications and as you age.

Heart arrhythmia

This condition (also known as an abnormal heart rate) is when your heart beats too fast, too slow or in a way that causes a sudden decrease in the blood supply to your brain. Any of these can make you feel faint.

Medications

Medicines prescribed for pain, heart conditions and high blood pressure can affect your circulatory system and — you guessed it — feeling dizzy. If it happens a lot, talk to your doctor about adjusting your dosage.

Dehydration

Not drinking enough fluids can cause nausea, weakness, dizziness, low blood pressure and fainting. The good news: Rehydrating will alleviate your symptoms quickly.

Anemia

Anemia is a lack of healthy red blood cells or hemoglobin in your blood, which carry oxygen to your organs — including your brain. The hallmark of anemia is tiredness, but it can also cause you to feel faint and dizzy.

Autonomic neuropathy

This nerve disease disrupts electrical signals between your brain and heart, blood vessels and sweat glands. Feelings of faintness come from its effect on your heart rate and blood pressure.

Stress and panic attacks

Ever had an anxiety attack? You probably breathed more rapidly and deeply, both of which can lead to lightheadedness and dizziness.

What to do if you feel faint

When you get that lightheaded feeling, lie down or sit down and place your head between your knees. 

“The most important thing to do if you feel faint is to get to a safe place,” says Crispell. “By doing so, if you do lose consciousness, you’ll avoid injury from falling or bumping your head.”

After the fainting spell passes, contact your healthcare provider as soon as possible for a checkup. A trained medical professional can pinpoint the exact cause of your presyncope.

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Meet Lia Crispell, CRNP

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